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Sample records for spontaneous water imbibition

  1. Spontaneous imbibition of water and determination of effective contact angles in the Eagle Ford Shale Formation using neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    DiStefano, Victoria H.; Cheshire, Michael C.; McFarlane, Joanna; Kolbus, Lindsay M.; Hale, Richard E.; Perfect, Edmund; Bilheux, Hassina Z.; Santodonato, Louis J.; Hussey, Daniel S.; Jacobson, David L.; LaManna, Jacob M.; Bingham, Philip R.; Starchenko, Vitaliy; Anovitz, Lawrence M.

    2017-10-01

    Understanding of fundamental processes and prediction of optimal parameters during the horizontal drilling and hydraulic fracturing process results in economically effective improvement of oil and natural gas extraction. Although, the modern analytical and computational models can capture fracture growth, there is a lack of experimental data on spontaneous imbibition and wettability in oil and gas reservoirs for the validation of further model development. In this work, we used neutron imaging to measure the spontaneous imbibition of water into fractures of Eagle Ford Shale with known geometries and fracture orientations. An analytical solution for a set of nonlinear second-order differential equations was applied to the measured imbibition data to determine effective contact angles. The analytical solution fit the measured imbibition data reasonably well and determined effective contact angles were slightly higher than static contact angles due to effects of in-situ changes in velocity, surface roughness, and heterogeneity of mineral surfaces on the fracture surface. Additionally, small fracture widths may have retarded imbibition and affected model fits, which suggests that average fracture widths are not satisfactory for modeling imbibition in natural systems.

  2. Ultrasonic monitoring of spontaneous imbibition experiments: Precursory moisture diffusion effects ahead of water front

    Science.gov (United States)

    David, Christian; Sarout, Joël.; Dautriat, Jérémie; Pimienta, Lucas; Michée, Marie; Desrues, Mathilde; Barnes, Christophe

    2017-07-01

    Fluid substitution processes have been investigated in the laboratory on 14 carbonate and siliciclastic reservoir rock analogues through spontaneous imbibition experiments on vertical cylindrical specimens with simultaneous ultrasonic monitoring and imaging. The motivation of our study was to identify the seismic attributes of fluid substitution in reservoir rocks and to link them to physical processes. It is shown that (i) the P wave velocity either decreases or increases when the capillary front reaches the Fresnel clearance zone, (ii) the P wave amplitude is systematically impacted earlier than the velocity is, (iii) this precursory amplitude decrease occurs when the imbibition front is located outside of the Fresnel zone, and (iv) the relative variation of the P wave amplitude is always much larger than that of the P wave velocity. These results suggest that moisture diffuses into the pore space ahead of the water front. This postulate is further supported by a quantitative analysis of the time evolution of the observed P wave amplitudes. In a sense, P wave amplitude acts as a precursor of the arrival of the capillary front. This phenomenon is used to estimate the effective diffusivity of moisture in the tested rocks. The effective moisture diffusivity estimated from the ultrasonic data is strongly correlated with permeability: a power law with exponent 0.96 predicts permeability from ultrasonic monitoring within a factor 3 without noticeable bias. When the effective diffusivity is high, moisture diffusion affects ultrasonic P wave attributes even before the imbibition starts and impacts the P wave reflectivity as evidenced by the variations recorded in the waveform coda.

  3. Numerical simulation of counter-current spontaneous imbibition in water-wet fractured porous media: Influences of water injection velocity, fracture aperture, and grains geometry

    Science.gov (United States)

    Jafari, Iman; Masihi, Mohsen; Nasiri Zarandi, Masoud

    2017-11-01

    Counter-current spontaneous imbibition (SI), in which water and oil flow through the same face in opposite directions, is known as one of the most significant oil recovery mechanisms in naturally fractured reservoirs; however, this mechanism has not received much attention. Understanding the dynamic of water-oil displacement during counter-current SI is very challenging because of simultaneous impacts of multiple factors including geometry complexity and heterogeneity of naturally fractured reservoir materials, e.g., high permeability contrast between the rock matrix and fracture, wettability, and porosity. This study investigates the effects of water injection velocity, fracture aperture, and grain shape during counter-current SI at pore-scale. A robust finite element solver is used to solve the governing equations of multiphase flow, which are the coupled Navier-Stokes and Cahn-Hilliard phase-field equations. The results showed that the case with the highest injection velocity (uinj = 5 mm/s) recovered more than 15% of the matrix oil at the early times and then reached its ultimate recovery factor. However, in the case of the lowest injection velocity, i.e., uinj = 0.05 mm/s, the lowest imbibition rate was observed at the early times, but ultimately 23% of the matrix oil was recovered. The model with uinj = 5 mm/s was able to capture some pore-level mechanisms such as snap-off, oil film thinning, interface coalescence, and water film bridging. The obtained results revealed that changing the fracture aperture has a slight effect on the imbibition rate at the earlier times and ultimate recoveries would be almost equal. To assess the influences of grain shape on the imbibition process, the simulated domain was reconstructed with cubic grains. It was noticed that because of higher permeability and porosity, relatively larger oil drops were formed and resulted in higher oil recovery compared with the model with spherical grains. The developed model can be used as a

  4. Improved Oil Recovery in Chalk. Spontaneous Imbibition affected by Wettability, Rock Framework and Interfacial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Milter, J.

    1996-12-31

    The author of this doctoral thesis aims to improve the oil recovery from fractured chalk reservoirs, i.e., maximize the area of swept zones and their displacement efficiencies. In order to identify an improved oil recovery method in chalk, it is necessary to study wettability of calcium carbonate and spontaneous imbibition potential. The thesis contains an investigation of thin films and wettability of single calcite surfaces. The results of thin film experiments are used to evaluate spontaneous imbibition experiments in different chalk types. The chalk types were described detailed enough to permit considering the influence of texture, pore size and pore throat size distributions, pore geometry, and surface roughness on wettability and spontaneous imbibition. Finally, impacts of interfacial tension by adding anionic and cationic surfactants to the imbibing water phase are studied at different wettabilities of a well known chalk material. 232 refs., 97 figs., 13 tabs.

  5. Rapid imbibition of water in fractures within unsaturated sedimentary rock

    Science.gov (United States)

    Cheng, C.-L.; Perfect, E.; Donnelly, B.; Bilheux, H. Z.; Tremsin, A. S.; McKay, L. D.; DiStefano, V. H.; Cai, J. C.; Santodonato, L. J.

    2015-03-01

    The spontaneous imbibition of water and other liquids into gas-filled fractures in variably-saturated porous media is important in a variety of engineering and geological contexts. However, surprisingly few studies have investigated this phenomenon. We present a theoretical framework for predicting the 1-dimensional movement of water into air-filled fractures within a porous medium based on early-time capillary dynamics and spreading over the rough surfaces of fracture faces. The theory permits estimation of sorptivity values for the matrix and fracture zone, as well as a dispersion parameter which quantifies the extent of spreading of the wetting front. Quantitative data on spontaneous imbibition of water in unsaturated Berea sandstone cores were acquired to evaluate the proposed model. The cores with different permeability classes ranging from 50 to 500 mD and were fractured using the Brazilian method. Spontaneous imbibition in the fractured cores was measured by dynamic neutron radiography at the Neutron Imaging Prototype Facility (beam line CG-1D, HFIR), Oak Ridge National Laboratory. Water uptake into both the matrix and the fracture zone exhibited square-root-of-time behavior. The matrix sorptivities ranged from 2.9 to 4.6 mm s-0.5, and increased linearly as the permeability class increased. The sorptivities of the fracture zones ranged from 17.9 to 27.1 mm s-0.5, and increased linearly with increasing fracture aperture width. The dispersion coefficients ranged from 23.7 to 66.7 mm2 s-1 and increased linearly with increasing fracture aperture width and damage zone width. Both theory and observations indicate that fractures can significantly increase spontaneous imbibition in unsaturated sedimentary rock by capillary action and surface spreading on rough fracture faces. Fractures also increase the dispersion of the wetting front. Further research is needed to investigate this phenomenon in other natural and engineered porous media.

  6. Surface hydration drives rapid water imbibition into strongly hydrophilic nanopores.

    Science.gov (United States)

    Fang, Chao; Qiao, Rui

    2017-08-09

    The imbibition of liquids into nanopores plays a critical role in numerous applications, and most prior studies focused on imbibition due to capillary flows. Here we report molecular simulations of the imbibition of water into single mica nanopores filled with pressurized gas. We show that, while capillary flow is suppressed by the high gas pressure, water is imbibed into the nanopore through surface hydration in the form of monolayer liquid films. As the imbibition front moves, the water film behind it gradually densifies. Interestingly, the propagation of the imbibition front follows a simple diffusive scaling law. The effective diffusion coefficient of the imbibition front, however, is more than ten times larger than the diffusion coefficient of the water molecules in the water film adsorbed on the pore walls. We clarify the mechanism for the rapid water imbibition observed here.

  7. Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Standnes, Dag Chun

    2001-09-01

    The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

  8. Fractal analysis of fracture increasing spontaneous imbibition in porous media with gas-saturated

    KAUST Repository

    Cai, Jianchao

    2013-08-01

    Spontaneous imbibition (SI) of wetting liquid into matrix blocks due to capillary pressure is regarded as an important recovery mechanism in low permeability fractured reservoir. In this paper, an analytical model is proposed for characterizing SI horizontally from a single plane fracture into gas-saturated matrix blocks. The presented model is based on the fractal character of pores in porous matrix, with gravity force included in the entire imbibition process. The accumulated mass of wetting liquid imbibed into matrix blocks is related to a number of factors such as contact area, pore fractal dimension, tortuosity, maximum pore size, porosity, liquid density and viscosity, surface tension, contact angle, as well as height and tilt angle of the fracture. The mechanism of fracture-enhanced SI is analyzed accordingly. Because of the effect of fracture, the gravity force is positive to imbibition process. Additionally, the farther away from the fracture top of the pore, the more influential the hydrostatic pressure is upon the imbibition action. The presented fractal analysis of horizontal spontaneous imbibition from a single fracture could also shed light on the scaling study of the mass transfer function between matrix and fracture system of fractured reservoirs. © 2013 World Scientific Publishing Company.

  9. Modeling of wettability alteration during spontaneous imbibition of mutually soluble solvents in mixed wet fractured reservoirs

    NARCIS (Netherlands)

    Chahardowli, M.; Bruining, J.

    2014-01-01

    Mutually-soluble solvents can enhance oil recovery both in mixed-wet fractured reservoirs. When a partially waterwet matrix is surrounded by an immiscible wetting phase in the fracture, spontaneous imbibition is the most important production mechanism. Initially, the solvent moves with the imbibing

  10. Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery from Fractured Reservoirs by Spontaneous Imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Zhengxin Tong; Evren Unsal; Siluni Wickramathilaka; Shaochang Wo; Peigui Yin

    2008-06-30

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the non-wetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  11. FUNDAMENTALS OF RESERVOIR SURFACE ENERGY AS RELATED TO SURFACE PROPERTIES, WETTABILITY, CAPILLARY ACTION, AND OIL RECOVERY FROM FRACTURED RESERVOIRS BY SPONTANEOUS IMBIBITION

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Peigui Yin; Shaochang Wo

    2004-10-01

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the nonwetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  12. Fundamentals of reservoir surface energy as related to surface properties, wettability, capillary action, and oil recovery from fractured reservoirs by spontaneous imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Jason Zhengxin Tong; Peigui Yin; Shaochang Wo

    2006-06-08

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the non-wetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  13. Effect of the meniscus contact angle during early regimes of spontaneous imbibition in nanochannels

    DEFF Research Database (Denmark)

    Karna, Nabin Kumar; Oyarzua, Elton; Walther, Jens Honore

    2016-01-01

    meniscus. Bosanquet's equation overcomes this problem by taking into account fluid inertia predicting an initial imbibition regime with constant velocity. Nevertheless, the initial constant velocity as predicted by Bosanquet's equation is much greater than those observed experimentally. In the present...... study, large scale atomistic simulations are conducted to investigate capillary imbibition of water in slit silica nanochannels with heights between 4 and 18 nm. We find that the meniscus contact angle remains constant during the inertial regime and its value depends on the height of the channel. We...... also find that the meniscus velocity computed at the channel entrance is related to the particular value of the meniscus contact angle. Moreover, during the subsequent visco-inertial regime, as the influence of viscosity increases, the meniscus contact angle is found to be time dependent for all...

  14. Water imbibition by mica pores: what happens when capillary flow is suppressed?

    Science.gov (United States)

    Fang, Chao; Qiao, Rui

    2017-11-01

    The imbibition of liquids into porous media plays a critical role in numerous applications. Most prior studies focused on imbibition driven by capillary flows. In this work, we study the imbibition of water into slit-shaped mica pores filled with pressurized methane using molecular simulations. Despite that capillary flow is suppressed by the high gas pressure, water is imbibed into the pore as monolayer liquid films. Since the classical hydrodynamic flow is not readily applicable for the monolayer water film propagating on the mica wall and the imbibition is driven by the strong affinity of water molecules to the mica walls, the observed imbibition is best taken as surface hydration. We show that the dynamics of water's imbibition front follows a simple diffusive scaling law. The effective diffusion coefficient of the imbibition front, however, is more than ten times larger than the diffusion coefficient of the water molecules in the water film adsorbed on the mica walls. Using a molecular theory originally developed for the spreading of monolayer films on solid substrates, we clarify the mechanism underlying the rapid water imbibition observed here.

  15. Nano-scale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks

    Science.gov (United States)

    Akbarabadi, Morteza; Saraji, Soheil; Piri, Mohammad; Georgi, Dan; Delshad, Mohammad

    2017-09-01

    We investigated spontaneous imbibition behavior, three-dimensional fluid occupancy maps, and in-situ wettability at the nano scale in five ultra-tight and shale reservoir rock samples. For this purpose, we developed a novel technique by integrating a custom-built in-situ miniature fluid-injection module with a non-destructive high-resolution X-ray imaging system. Small cylindrical core samples (15-60 μm in diameter) were prepared from reservoir rocks using Focused-Ion Beam (FIB) milling technique. The pore network inside the samples were first characterized using ultra-high resolution three-dimensional images obtained at initial state by X-ray nano-tomography (Nano-CT) and FIB-Scanning Electron Microscopy (FIB-SEM) techniques at the nano scale. The petrophysical parameters, including porosity, permeability, pore-size distribution, and organic content were computed for each sample using image analysis. We then performed series of imbibition experiments using brine, oil, and surfactant solutions on each core sample. We observed that both oil and brine phases spontaneously imbibe into the pore network of the rock samples at various quantities. We also, for the first time, examined fluid distribution in individual pores and found a complex wettability behavior at the pore scale in the reservoir rock samples. Three pore types were identified with water-wet, oil-wet, and fractionally-wet behaviors. This work opens a new path to developing an improved understanding of the pore-level physics involved in multi-phase flow and transport not only in tight rock samples but also in other nanoporous material used in different science and engineering applications.

  16. Models of water imbibition in untreated and treated porous media validated by quantitative magnetic resonance imaging

    Science.gov (United States)

    Gombia, M.; Bortolotti, V.; Brown, R. J. S.; Camaiti, M.; Fantazzini, P.

    2008-05-01

    Fluid imbibition affects almost every activity that directly or indirectly involves porous media, including oil reservoir rocks, soils, building materials, and countless others, including biological materials. In this paper, magnetic resonance imaging (MRI) has been applied to study water imbibition in a porous medium, in which capillary properties are artificially changed. As a model system, samples of Lecce stone, a material of cultural heritage interest, were analyzed before and after treatment with a protective polymer (Silirain-50 or Paraloid PB72). By using MRI, we can visualize the presence of water inside each sample and measure the height z(t ) reached by the wetting front as a function of time during experiments of capillary absorption before and after treatment. The sorptivity S, defined as the initial slope of z versus t1/2, has been determined before treatment and through both treated and untreated faces after treatment. Very good fits to the data were obtained with theoretical and empirical models of absorption kinetics, starting from the Washburn model for capillary rise, adapted by others to homogeneous porous media, and modified by us for application to a sample having a thin low-permeability layer on either surface as a result of a treatment process. This gives us parameters to quantify the effects on imbibition of the changes in the capillary properties. It is known that the Paraloid treatment preferentially affects the larger pore channels and the Silirain the smaller, and our results show this and illustrate the roles played by the different classes of pore sizes.

  17. The role of fracture coatings on water imbibition into unsaturated tuff from Yucca Mountain

    International Nuclear Information System (INIS)

    Chekuri, V.S.; Tyler, S.W.; Fordham, J.W.

    1995-11-01

    Studies dealing with fracture flow at Yucca Mountain have generally assumed that any water flowing down in a fracture will be absorbed by the porous matrix. However, a thin lining of low permeability material on the fracture walls may significantly impede imbibition into the matrix of unsaturated tuff. In this research, imbibition was measured across the fracture surfaces in the laboratory. Samples were collected from surface outcrops of Tiva Canyon and Topopah Spring members of the Paintbrush tuff near Yucca Mountain. Sorptivity, a convenient measure of imbibition, was used to investigate the changes in hydraulic properties as a result of fracture coatings. Results from experimental analysis of Topopah Spring tuff showed decreased sorptivity across coated fracture surfaces. Statistically, the coatings on the Tiva Canyon samples do not significantly affect sorptivity. Scanning Electron Microscope analysis shows that coatings on the s grit Tiva Canyon samples are made up of iron, aluminum and to some extent magnesium. Coating material on the Topopah Spring samples is made up of calcium, magnesium, aluminum and iron. Coating significantly reduces the sorptivity for the Topopah Spring tuff. Numerical results are presented to show the effect of fracture coatings on water infiltration down a vertical fracture in simulated tuff. For the Topopah Spring tuff, the wetting front in the coated fracture travels deeper in the fracture and less into the matrix compared to the wetting front in the uncoated fracture. For the Tiva Canyon tuff, the wetting front in the uncoated fracture travels deeper in the fracture and less into the matrix as compared to the wetting front in the coated fracture

  18. A Neutron Radiology Application to Natural Absorption (Imbibition) of Water into Porous Rocks

    International Nuclear Information System (INIS)

    Middleton, M.F.; de Beer, Frikkie

    2005-01-01

    Full text: Dynamic neutron radiology provides a method of evaluating the concentration of water in porous media. A study of water imbibition (absorption of a wetting liquid into a porous medium with a non-wetting fluid, air), which is imaged by dynamic neutron radiology , provides an excellent method of determining the fluid diffusivity parameter, D. This parameter enables one to model water-air regimes in surface hydrological systems and aquifers; analogies can also be made for deeper petroleum systems. A methodology of pixel-by-pixel analysis for the estimation of water concentration, as a function of time under natural absorption conditions, is proposed which provides a good mapping of D within a rock sample. The proposed method entails the discrete mapping of the differential equation for horizontal flow of a partial water concentration, c, in an air-filled rock/soil. (authors)

  19. Effects of different depth of grain colour on antioxidant capacity during water imbibition in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Shin, Oon Ha; Kim, Dae Yeon; Seo, Yong Weon

    2017-07-01

    The importance of the effect of phytochemical accumulation in wheat grain on grain physiology has been recognised. In this study, we tracked phytochemical concentration in the seed coat of purple wheat during the water-imbibition phase and also hypothesised that the speed of germination was only relevant to its initial phytochemical concentration. The results indicate that the speed of germination was significantly reduced in the darker grain groups within the purple wheat. Total phenol content was slightly increased in all groups compared to their initial state, but the levels of other phytochemicals varied among groups. It is revealed that anthocyanin was significantly degraded during the water imbibition stage. Also, the activities of peroxidase, ascorbate peroxidase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase in each grain colour group did not correlated with germination speed. Overall antioxidant activity was reduced as imbibition progressed in each group. Generally, darker grain groups showed higher total antioxidant activities than did lighter grain groups. These findings suggested that the reduced activity of reactive oxygen species, as controlled by internal antioxidant enzymes and phytochemicals, related with germination speed during the water imbibition stage in grains with greater depth of purple colouring. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Effects of microstructure on water imbibition in sandstones using X-ray computed tomography and neutron radiography

    Science.gov (United States)

    Zhao, Yixin; Xue, Shanbin; Han, Songbai; Chen, Zhongwei; Liu, Shimin; Elsworth, Derek; He, Linfeng; Cai, Jianchao; Liu, Yuntao; Chen, Dongfeng

    2017-07-01

    Capillary imbibition in variably saturated porous media is important in defining displacement processes and transport in the vadose zone and in low-permeability barriers and reservoirs. Nonintrusive imaging in real time offers the potential to examine critical impacts of heterogeneity and surface properties on imbibition dynamics. Neutron radiography is applied as a powerful imaging tool to observe temporal changes in the spatial distribution of water in porous materials. We analyze water imbibition in both homogeneous and heterogeneous low-permeability sandstones. Dynamic observations of the advance of the imbibition front with time are compared with characterizations of microstructure (via high-resolution X-ray computed tomography (CT)), pore size distribution (Mercury Intrusion Porosimetry), and permeability of the contrasting samples. We use an automated method to detect the progress of wetting front with time and link this to square-root-of-time progress. These data are used to estimate the effect of microstructure on water sorptivity from a modified Lucas-Washburn equation. Moreover, a model is established to calculate the maximum capillary diameter by modifying the Hagen-Poiseuille and Young-Laplace equations based on fractal theory. Comparing the calculated maximum capillary diameter with the maximum pore diameter (from high-resolution CT) shows congruence between the two independent methods for the homogeneous silty sandstone but less effectively for the heterogeneous sandstone. Finally, we use these data to link observed response with the physical characteristics of the contrasting media—homogeneous versus heterogeneous—and to demonstrate the sensitivity of sorptivity expressly to tortuosity rather than porosity in low-permeability sandstones.

  1. Effect of Imbibition and Irrigation Water Salinity Levels on Germination of Amburana cearensis (A. C. Smith.

    Directory of Open Access Journals (Sweden)

    Beatriz de Abreu Araújo

    2016-12-01

    Full Text Available The aim of this work was to evaluate the seedling emergence of A. cearensis as a function of the imbibition (zero and 24 hours and salinity (0.0, 1.5, 3.0, 4.5, 6.0 dS m-¹. The experiment was conducted in the greenhouse and Plant Health Laboratory of the Federal Institute of Ceará campus Sobral, from 12/2014 to 01/2015. The variables were percentage (%E, speed index (ESI, emergence mean time (EMT, number of leaves (NL, stem diameter (SD, root length (RL, dry weight of shoots (DWS and dry weight of roots (DWR. The seedling emergence of A. cearensis is negatively affected by salinity from 4.5 dS m-1.

  2. A generalized power-law scaling law for a two-phase imbibition in a porous medium

    KAUST Repository

    El-Amin, Mohamed

    2013-11-01

    Dimensionless time is a universal parameter that may be used to predict real field behavior from scaled laboratory experiments in relation to imbibition processes in porous media. Researchers work to nondimensionalize the time has been through the use of parameters that are inherited to the properties of the moving fluids and the porous matrix, which may be applicable to spontaneous imbibition. However, in forced imbibition, the dynamics of the process depends, in addition, on injection velocity. Therefore, we propose the use of scaling velocity in the form of a combination of two velocities, the first of which (the characteristic velocity) is defined by the fluid and the porous medium parameters and the second is the injection velocity, which is a characteristic of the process. A power-law formula is suggested for the scaling velocity such that it may be used as a parameter to nondimensionalize time. This may reduce the complexities in characterizing two-phase imbibition through porous media and works well in both the cases of spontaneous and forced imbibition. The proposed scaling-law is tested against some oil recovery experimental data from the literature. In addition, the governing partial differential equations are nondimensionalized so that the governing dimensionless groups are manifested. An example of a one-dimensional countercurrent imbibition is considered numerically. The calculations are carried out for a wide range of Ca and Da to illustrate their influences on water saturation as well as relative water/oil permeabilities. © 2013 Elsevier B.V.

  3. Water uptake and oil distribution during imbibition of seeds of western white pine (Pinus monticola Dougl. ex D. Don) monitored in vivo using magnetic resonance imaging.

    Science.gov (United States)

    Terskikh, Victor V; Feurtado, J Allan; Ren, Chengwei; Abrams, Suzanne R; Kermode, Allison R

    2005-04-01

    Dry or fully imbibed seeds of western white pine (Pinus monticola Dougl. ex D. Don) were studied using high-resolution magnetic resonance imaging (MRI). Analyses of the dry seed revealed many of the gross anatomical features of seed structure. Furthermore, the non-invasive nature of MRI allowed for a study of the dynamics of water and oil distribution during in situ imbibition of a single seed with time-lapse chemical shift selective MRI. During soaking of the dry seed, water penetrated through the seed coat and megagametophyte. The cotyledons of the embryo (located in the chalazal end of the seed) were the first to show hydration followed by the hypocotyl and later the radicle. After penetrating the seed coat, water in the micropylar end of the seed likely also contributed to further hydration of the embryo; however, the micropyle itself did not appear to be a site for water entry into the seed. A model that describes the kinetics of the earlier stages of imbibition is proposed. Non-viable pine seeds captured with MRI displayed atypical imbibition kinetics and were distinguished by their rapid and uncontrolled water uptake. The potential of MR microimaging for detailed studies of water uptake and distribution during the soaking, moist chilling ("stratification"), and germination of conifer seeds is discussed.

  4. Simulation of counter-current imbibition in water-wet fractured reservoirs based on discrete-fracture model

    Directory of Open Access Journals (Sweden)

    Wang Yueying

    2017-08-01

    Full Text Available Isolated fractures usually exist in fractured media systems, where the capillary pressure in the fracture is lower than that of the matrix, causing the discrepancy in oil recoveries between fractured and non-fractured porous media. Experiments, analytical solutions and conventional simulation methods based on the continuum model approach are incompetent or insufficient in describing media containing isolated fractures. In this paper, the simulation of the counter-current imbibition in fractured media is based on the discrete-fracture model (DFM. The interlocking or arrangement of matrix and fracture system within the model resembles the traditional discrete fracture network model and the hybrid-mixed-finite-element method is employed to solve the associated equations. The Behbahani experimental data validates our simulation solution for consistency. The simulation results of the fractured media show that the isolated-fractures affect the imbibition in the matrix block. Moreover, the isolated fracture parameters such as fracture length and fracture location influence the trend of the recovery curves. Thus, the counter-current imbibition behavior of media with isolated fractures can be predicted using this method based on the discrete-fracture model.

  5. Effect of electroosmotic flow on brine imbibition in porous media

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2009-03-01

    Full Text Available Based on Darcy's Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to various extents not only related to the rock permeability and characteristic length, the fluid viscosity, the oil-water interface tension and the gravity of the imbibing brine, but also to the fluid dielectric permittivity, zeta potential, applied electric field direction, and strength. Imbibition experiments with electric fields that are different in direction and strength were conducted, showing that application of a positive electric field enhances the imbibition velocity and increases the imbibition recovery ratio, while application of a negative electric field reduces the imbibition velocity and decreases the imbibition recovery ratio. The imbibition recovery ratio with a positive electric field increases with the strength of the electric field, and the imbibition recovery ratio with a negative electric field is lower than that without an electric field.

  6. Improvements in scaling of counter-current imbibition recovery curves using a shape factor including permeability anisotropy

    Science.gov (United States)

    Abbasi, Jassem; Sarafrazi, Shiva; Riazi, Masoud; Ghaedi, Mojtaba

    2018-02-01

    Spontaneous imbibition is the main oil production mechanism in the water invaded zone of a naturally fractured reservoir (NFR). Different scaling equations have been presented in the literature for upscaling of core scale imbibition recovery curves to field scale matrix blocks. Various scale dependent parameters such as gravity effects and boundary influences are required to be considered in the upscaling process. Fluid flow from matrix blocks to the fracture system is highly dependent on the permeability value in the horizontal and vertical directions. The purpose of this study is to include permeability anisotropy in the available scaling equations to improve the prediction of imbibition assisted oil production in NFRs. In this paper, a commercial reservoir simulator was used to obtain imbibition recovery curves for different scenarios. Then, the effect of permeability anisotropy on imbibition recovery curves was investigated, and the weakness of the existing scaling equations for anisotropic rocks was demonstrated. Consequently, an analytical shape factor was introduced that can better scale all the curves related to anisotropic matrix blocks.

  7. Effect of Surfactant Concentration in the Emulsions on the Process of Oleophilic Porous Structures Imbibition

    Directory of Open Access Journals (Sweden)

    Shtyka Olga S.

    2016-01-01

    Full Text Available The spontaneous imbibition has been a subject of the scientific interest being a background process for numerous industrial technologies and occurring in the natural environment. In literature the experimental and theoretical results regarding this phenomenon describe a media imbibition with single-phase liquids and the relation between the process rate and media characteristics. The imbibition of oleophilic porous structures with two-phase liquids, only one phase of which was wetting, is an objective of the current publication. The main purpose is to estimate the influence of both surfactant fraction and the dispersed phase concentration on the mentioned process. The imbibition rate was investigated during model experiments with stabilized oil-in-water emulsions having the dispersed phase concentrations of 10 vol%, 30 vol% and 50 vol%. The prepared emulsions differed with fraction of the added surfactant, i.e. 1 vol%, 2 vol% and 5 vol%. The obtained results allowed to conclude that at the him≥0.02 m, the dispersed phase concentration and viscosity decreased versus height. However, the raise of the surfactant fraction caused the increase of mass and height of the imbibed emulsions in porous medium. Moreover, this provided increasing of viscosity and a change of emulsions behaviour as a liquid.

  8. Método para determinar la cantidad de agua de imbibición a utilizar en la caña // Methodology to determine the amount of imbibition water to use in the sugar cane industry.

    Directory of Open Access Journals (Sweden)

    Félix González-Pérez

    2010-01-01

    Full Text Available ResumenSe hizo un estudio del uso del agua de imbibición en la industria del azúcar de caña de Cuba y, serevisaron más de 200 fuentes bibliográficas llegándose a conclusiones importantes en cuanto a lacantidad y temperatura del agua de imbibición, así como la revisión del esquema de imbibición másutilizado.A partir de aquí se obtiene un procedimiento para determinar la cantidad óptima de agua deimbibición teniendo en cuenta los precios actualizados del azúcar y el bagazo como combustible ypara otros usos, Es utilizado para su validación en dos empresas azucareras de la provincia deCienfuegos, se obtuvo que en las condiciones económicas actuales, es recomendable utilizar entre10,4 – 15,4 % caña en dependencia del uso que se le dé al bagazo y no entre 18-22 % caña como seviene haciendo históricamente, lo que permitió lograr un ahorro de agua de 66670,1 t, esto haceque se ahorren 9531.77 kWh de energía eléctrica por bombeo, permitiendo un efecto económicototal entre 22939,92 – 218505,47 USD.Palabras claves: imbibición, ingenios azucareros, energía______________________________________________________________AbstractA study was performed of the use of the water of imbibition in the industry of the sugar cane ofCuba and internationally. More than 200 bibliographical sources were reviewed reaching importantconclusions as far as the amount and temperature from the imbibition water, as well as the schemeused of imbibition water most commonly used.A very simple procedure is obtained to determine the optimal amount of imbibition waterconsidering the updated prices of the sugar and the bagasse as fuel and for other uses. It is appliedfor his validation in two sugar companies of the province of Cienfuegos. In the present economicconditions the results showed that it is advisable to use an amount of imbibition water between10.4 -15,4 % of the amount of cane processed based on the use of the bagasse and not between18-22% as it

  9. Modeling of gravity-imbibition and gravity-drainage processes: Analytic and numerical solutions

    DEFF Research Database (Denmark)

    Bech, N.; Jensen, O.K.; Nielsen, B.

    1991-01-01

    A matrix/fracture exchange model for a fractured reservoir simulator is described. Oil/water imbibition is obtained from a diffusion equation with water saturation as the dependent variable. Gas/oil gravity drainage and imbibition are calculated by taking into account the vertical saturation...... distribution in the matrix blocks....

  10. Ageing increases the sensitivity of neem (Azadirachta indica) seeds to imbibitional stress

    NARCIS (Netherlands)

    Neya, O.; Golovina, E.A.; Nijsse, J.; Hoekstra, F.A.

    2004-01-01

    Imbibitional stress was imposed on neem (Azadirachta indica) seeds by letting them soak for 1 h in water at unfavourable, low temperatures before further incubation at 30degreesC. Sensitivity to low imbibition temperatures increased with a decrease in seed moisture content (MC). To investigate a

  11. Experimental Study of Imbibition Characteristics of Silica Sol in Coal-Measure Mudstone Matrix

    Directory of Open Access Journals (Sweden)

    Dongjiang Pan

    2017-03-01

    Full Text Available Coal-measure mudstone is a typical dual-porosity media, and grouting in a matrix system is dominantly controlled by the imbibition effect for silica sol. This paper studies the imbibition effect using mudstone in the Huaibei mining area and silica sol as grouting material as an example. Groutability, driving force, and diffusion difficulty affecting the imbibition effect were tested by a mercury porosimeter, nanoparticle size analyzer, optical contact-angle measuring device, surface tension meter, and rotary viscosity meter. After finely grinding a mudstone sample, a pressureless imbibition process was conducted through nuclear magnetic resonance equipment for 216 h to study colloid spontaneous migration and phase characteristics. Results show that silica sol absorption rate follows a power function and that the spectrograms of T2 are distributed in a triple peak pattern, with a tendency to move to the right of vertex time. The paper lays a theoretical and experimental foundation for field grouting in the coal mine.

  12. Chilling temperature remodels phospholipidome of Zea mays seeds during imbibition.

    Science.gov (United States)

    Noblet, Agathe; Leymarie, Juliette; Bailly, Christophe

    2017-08-21

    Global warming is a major agricultural issue in the Northern hemisphere where higher temperatures are expected to be associated with restricted water availability. In Europe, for maize, earlier and further northward sowings are forecasted in order to avoid water deficit periods in the crop life cycle. However these conditions may compromise seed germination and stand establishment since they will take place at cold temperatures. It is urgent to better understand the molecular bases of response of germinating maize seeds to cold in order to design genotypes adapted to these novel agricultural practices. Here we have performed a global phospholipidomic study to profile changes in membrane reorganisation during seed imbibition at 10 °C of cold-tolerant and -sensitive maize hybrids. Using a Multiple Reaction Monitoring (MRM-MS/MS) method coupled with HPLC we have identified 80 distinct phospholipids. We show that seed sensitivity to cold temperatures during imbibition relies on the accumulation of saturated or poorly unsaturated fatty acids, whatever the phospholipid class. In contrast seeds of cold-tolerant hybrid accumulated polyunsaturated chains which was associated with lower electrolyte leakage during imbibition at 10 °C. The expression of fatty acid desaturase genes provides a molecular model of maize seed sensitivity to imbibitional chilling damage.

  13. Imbibition well stimulation via neural network design

    Science.gov (United States)

    Weiss, William

    2007-08-14

    A method for stimulation of hydrocarbon production via imbibition by utilization of surfactants. The method includes use of fuzzy logic and neural network architecture constructs to determine surfactant use.

  14. Analysis of interfacial curvature during drainage and imbibition

    Science.gov (United States)

    Armstrong, R. T.; Porter, M. L.; Wildenschild, D.

    2011-12-01

    Recent synchrotron-based tomographic data sets of oil-water drainage and imbibition scenarios have been analyzed to quantify phase saturations, interfacial curvature, and separate connected from disconnected fluid phases. This allows us to follow the drainage and imbibition processes in great detail, assess equilibrium states, and understand the effects of fluid phase disconnection and re-connection on the resulting capillary pressures and interfacial curvatures. This analysis also allows for estimating capillary pressure (Pc) based on calculated curvatures and comparison to Pc measured externally with a transducer. Results indicate good agreement between curvature-based and transducer-based measurements when the connected phase interfaces are considered. Curvature measurements show a strong dependence on whether an interface is formed by connected or disconnected phases. Assuming that at equilibrium curvature is constant, curvature differences between the connected and disconnected phase interfaces can be used as a metric to asses equilibrium. Over longer equilibration, the average curvature value, for all interfaces, approaches the average curvature value predicted by the pressure transducer. Overall, the results indicate good agreement between curvature -based and transducer-based Pc measurements and allow for a detailed assessment of interfacial curvature during drainage and imbibition.

  15. Interplay between shape and roughness in early-stage microcapillary imbibition.

    Science.gov (United States)

    Girardo, Salvatore; Palpacelli, Silvia; De Maio, Alessandro; Cingolani, Roberto; Succi, Sauro; Pisignano, Dario

    2012-02-07

    Flows in microcapillaries and associated imbibition phenomena play a major role across a wide spectrum of practical applications, from oil recovery to inkjet printing and from absorption in porous materials and water transport in trees to biofluidic phenomena in biomedical devices. Early investigations of spontaneous imbibition in capillaries led to the observation of a universal scaling behavior, known as the Lucas-Washburn (LW) law. The LW allows abstraction of many real-life effects, such as the inertia of the fluid, irregularities in the wall geometry, and the finite density of the vacuum phase (gas or vapor) within the channel. Such simplifying assumptions set a constraint on the design of modern microfluidic devices, operating at ever-decreasing space and time scales, where the aforementioned simplifications go under serious question. Here, through a combined use of leading-edge experimental and simulation techniques, we unravel a novel interplay between global shape and nanoscopic roughness. This interplay significantly affects the early-stage energy budget, controlling front propagation in corrugated microchannels. We find that such a budget is governed by a two-scale phenomenon: The global geometry sets the conditions for small-scale structures to develop and propagate ahead of the main front. These small-scale structures probe the fine-scale details of the wall geometry (nanocorrugations), and the additional friction they experience slows the entire front. We speculate that such a two-scale mechanism may provide a fairly general scenario to account for extra dissipative phenomena occurring in capillary flows with nanocorrugated walls.

  16. Roles of mucilage in Emilia fosbergii, a myxocarpic Asteraceae: Efficient seed imbibition and diaspore adhesion.

    Science.gov (United States)

    De-Paula, Orlando C; Marzinek, Juliana; Oliveira, Denise M T; Paiva, Élder A S

    2015-09-01

    Several angiosperm families have myxodiaspory, such as the Asteraceae in which cypselae are frequently wind-dispersed. The roles of mucilage in cypselae remain misunderstood, and the route of water uptake from substrate to embryo remains unknown. In this work, we analyze the fruits of Emilia fosbergii aiming to clarify how the water is absorbed and how the structure of the pericarp can be related to the processes of diaspore adhesion and seed imbibition. The anatomy and ultrastructure of the cypselae of Emilia fosbergii were analyzed with histochemical tests and light, scanning and transmission electron microscopy. We assessed the roles of mucilage in seed imbibition using apoplasmic tracing with Lucifer yellow and epifluorescence microscopy and in adhesion with a sand assay. We describe structural and ultrastructural aspects of the exocarpic cells, especially the mucilaginous twin hairs. Lucifer yellow was absorbed only by the twin hairs, the cells where water primarily enters the seed during seed imbibition. In the sand assay, the mucilage was adhesive. The twin hairs on the surface of the cypselae can play a dual role in the establishment of new plants of this species. First, these trichomes constitute the main passage for water intake, which is essential for seed imbibition and germination, and after imbibition, they release mucilage that can adhere the diaspore. Therefore, the presence of myxocarpy in Asteraceae could be important in anemochoric species to avoid secondary dispersal. © 2015 Botanical Society of America.

  17. Solar-Terrestrial Effects on Bean Seed Imbibition

    Science.gov (United States)

    Minorsky, P. V.

    2012-12-01

    Forty years ago, a lively debate ensued amongst biologists concerning the nature of biological rhythms. The "endogenous" school argued that biological rhythms that occur in the absence of any obvious environmental oscillation arise endogenously from within the organism itself. The "exogenous" school on the other hand proposed that subtle and pervasive exogenous factors (e.g., geomagnetic variations or cosmic radiation) underlie most biological rhythms. Much of the debate between the endogenous vs. exogenous schools focused on circadian (circa-24 h) rhythms in particular. The demonstration that circadian rhythms continue in orbiting spacecraft was widely regarded as the final nail in the coffin of the "exogenous" school, and the entire school sank into obscurity. Regrettably, the demise of the "exogenous" school also caused some interesting findings concerning non-circadian rhythms to fall into oblivion as well. Three different research groups, for example, reported that bean (Phaseolus vulgaris) seeds display rhythms in imbibition that have ~7- or ~14-day periodicities. Consistent with the idea of an exogenous synchronizer, these rhythms often occurred synchronously in bean seed populations located 1500 km apart. The present experiment was initiated with the intention of examining whether these ~7 and ~14 d oscillations in imbibition corresponded to oscillations in solar-terrestrial parameters. Three replicates of ~25 g of bean seeds (Phaseolus vulgaris cv. Provider) were weighed daily and placed into beakers containing 200 ml of distilled water at 25° C. This temperature was maintained by nesting the beakers inside larger, temperature-jacketed beakers through which water from a temperature-regulated water bath was circulated. Four hours later the experiments were terminated: the bean seeds were blotted and weighed. Experiments were conducted almost every day between 3 and 7 AM UT from Jan 18, 2007 to Feb 26, 2008. A major difference between the present study and

  18. Imbibition of ``Open Capillary'': Fundamentals and Applications

    Science.gov (United States)

    Tani, Marie; Kawano, Ryuji; Kamiya, Koki; Okumura, Ko

    2015-11-01

    Control or transportation of small amount of liquid is one of the most important issues in various contexts including medical sciences or pharmaceutical industries to fuel delivery. We studied imbibition of ``open capillary'' both experimentally and theoretically, and found simple scaling laws for both statics and dynamics of the imbibition, similarly as that of imbibition of capillary tubes. Furthermore, we revealed the existence of ``precursor film,'' which developed ahead of the imbibing front, and the dynamics of it is described well by another scaling law for capillary rise in a corner. Then, to show capabilities of open capillaries, we demonstrated two experiments by fabricating micro mixing devices to achieve (1) simultaneous multi-color change of the Bromothymol blue (BTB) solution and (2) expression of the green florescent protein (GFP). This research was partly supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan). M. T. is supported by the Japan Society for the Promotion of Science Research Fellowships for Young Scientists.

  19. Quantification of storage proteins during seed imbibition of native species from the brazilian caatinga vegetation

    Directory of Open Access Journals (Sweden)

    Fabrício Francisco Santos da Silva

    2016-08-01

    Full Text Available Poincianella pyramidalis (Fabaceae, Schinopsis brasiliensis (Anacardiaceae and Sideroxylon obtusifolium (Sapotaceae are native species of the Caatinga vegetation from northeastern Brazil and have both biological importance and potential economic uses. Little is known about the water uptake and degradation of storage proteins during seed germination of these species. The aim of this study was to evaluate the imbibition and quantify the amount of storage proteins during seed germination of P. pyramidalis, S. brasiliensis and S. obtusifolium. Two lots of S. obtusifolium seeds with different vigour were used. Four replicates of 20 seeds of P. pyramidalis, S. brasiliensis and S. obtusifolium, were sown onto gerboxes with blotting paper soaked in distilled water and incubated during 72, 200 and 624 hours. Before and after imbibition seeds were weighed and frozen at until the sequential extraction and analysis of the seed storage proteins. Based on our results, we conclude that seed germination of P. pyramidalis, S. brasiliensis and S. obtusifolium has a well-defined triphasic imbibition. All storage proteins content of P. pyramidalis and S. brasiliensis seeds degraded along with the seed imbibition. Likewise, the content of albumins, globulins and glutelins decreased as S. obtusifolium seeds absorbed water.

  20. Imbibition of wheat seeds: Application of image analysis

    Science.gov (United States)

    Lev, Jakub; Blahovec, Jiří

    2017-10-01

    Image analysis is widely used for monitoring seeds during germination, and it is often the final phase of germination that is subjected to the greatest attention. However, the initial phase of germination (the so-called imbibition) also exhibits interesting behaviour. This work shows that image analysis has significant potential in the imbibition. Herein, a total of 120 seeds were analysed during germination tests, and information about seed size and shape was stored and analysed. It was found that the imbibition can be divided into two newly defined parts. The first one (`abrupt imbibition') consists mainly of the swelling of the seed embryo part and lasts approximately one hour. The second one, referred to as `main imbibition', consists mainly of spatial expansion caused by imbibition in the other parts of the seed. The results presented are supported by the development of seed cross area and shape parameters, and by direct observation.

  1. Wettability and Oil Recovery by Imbibition and Viscous Displacement from Fractured and Heterogeneous Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Jill Buckley

    2006-04-01

    About one-half of U.S. oil reserves are held in carbonate formations. The remaining oil in carbonate reservoirs is regarded as the major domestic target for improved oil recovery. Carbonate reservoirs are often fractured and have great complexity even at the core scale. Formation evaluation and prediction is often subject to great uncertainty. This study addresses quantification of crude oil/brine/rock interactions and the impact of reservoir heterogeneity on oil recovery by spontaneous imbibition and viscous displacement from pore to field scale. Wettability-alteration characteristics of crude oils were measured at calcite and dolomite surfaces and related to the properties of the crude oils through asphaltene content, acid and base numbers, and refractive index. Oil recovery was investigated for a selection of limestones and dolomites that cover over three orders of magnitude in permeability and a factor of four variation in porosity. Wettability control was achieved by adsorption from crude oils obtained from producing carbonate reservoirs. The induced wettability states were compared with those measured for reservoir cores. The prepared cores were used to investigate oil recovery by spontaneous imbibition and viscous displacement. The results of imbibition tests were used in wettability characterization and to develop mass transfer functions for application in reservoir simulation of fractured carbonates. Studies of viscous displacement in carbonates focused on the unexpected but repeatedly observed sensitivity of oil recovery to injection rate. The main variables were pore structure, mobility ratio, and wettability. The potential for improved oil recovery from rate-sensitive carbonate reservoirs by increased injection pressure, increased injectivity, decreased well spacing or reduction of interfacial tension was evaluated.

  2. Spontaneous Recovery of Human Spatial Memory in a Virtual Water Maze

    Science.gov (United States)

    Luna, David; Martínez, Héctor

    2015-01-01

    The occurrence of spontaneous recovery in human spatial memory was assessed using a virtual environment. In Experiment 1, spatial memory was established by training participants to locate a hidden platform in a virtual water maze using a set of four distal landmarks. In Experiment 2, after learning about the location of a hidden platform, the…

  3. The spontaneous synchronized dance of pairs of water molecules

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, Luiz F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade de Brasília, 70910-900 Brasília (Brazil); Cappelletti, David, E-mail: david.cappelletti@unipg.it; Pirani, Fernando [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia (Italy)

    2014-03-28

    Molecular beam scattering experiments have been performed to study the effect of long-range anisotropic forces on the collision dynamics of two small polar molecules. The main focus of this paper is on water, but also ammonia and hydrogen sulphide molecules have been investigated, and some results will be anticipated. The intermolecular distances mainly probed are of the order of 1 nm and therefore much larger than the molecular dimensions. In particular, we have found that the natural electric field gradient, generated by different spatial orientations of the permanent electric dipoles, is able to promote the transformation of free rotations into coupled pendular states, letting the molecular partners involved in the collision complex swinging to and fro around the field direction. This long-ranged concerted motion manifested itself as large increases of the magnitude of the total integral cross section. The experimental findings and the theoretical treatment developed to shed light on the details of the process suggest that the transformation from free rotations to pendular states depends on the rotational level of both molecules, on the impact parameter, on the relative collision velocity, on the dipole moment product and occurs in the time scale of picoseconds. The consequences of this intriguing phenomenon may be important for the interpretation and, in perspective, for the control of elementary chemical and biological processes, given by polar molecules, ions, and free radicals, occurring in several environments under various conditions.

  4. Rethinking Historical and Cultural Source of Spontaneous Mental Models of Water Cycle: In the Perspective of South Korea

    Science.gov (United States)

    Nam, Younkyeong

    2012-01-01

    This review explores Ben-Zvi Assaraf, Eshach, Orion, and Alamour's paper titled "Cultural Differences and Students' Spontaneous Models of the Water Cycle: A Case Study of Jewish and Bedouin Children in Israel" by examining how the authors use the concept of spontaneous mental models to explain cultural knowledge source of Bedouin…

  5. Cultural Differences and Students' Spontaneous Models of the Water Cycle: A Case Study of Jewish and Bedouin Children in Israel

    Science.gov (United States)

    Ben-Zvi Assaraf, Orit; Eshach, Haim; Orion, Nir; Alamour, Yousif

    2012-01-01

    The present research aims at pinpointing differences in spontaneous and non-spontaneous mental models of water cycle conceptions of two 4th grade student groups: the Jewish residents of a small provincial town and a group of students from an indigenous Bedouin community. Students' conceptions were elicited using the Repertory Grid technique as…

  6. Formation of oil-in-water emulsions from natural emulsifiers using spontaneous emulsification: sunflower phospholipids.

    Science.gov (United States)

    Komaiko, Jennifer; Sastrosubroto, Ashtri; McClements, David Julian

    2015-11-18

    This study examined the possibility of producing oil-in-water emulsions using a natural surfactant (sunflower phospholipids) and a low-energy method (spontaneous emulsification). Spontaneous emulsification was carried out by titrating an organic phase (oil and phospholipid) into an aqueous phase with continuous stirring. The influence of phospholipid composition, surfactant-to-oil ratio (SOR), initial phospholipids location, storage time, phospholipid type, and preparation method was tested. The initial droplet size depended on the nature of the phospholipid used, which was attributed to differences in phospholipid composition. Droplet size decreased with increasing SOR and was smallest when the phospholipid was fully dissolved in the organic phase rather than the aqueous phase. The droplets formed using spontaneous emulsification were relatively large (d > 10 μm), and so the emulsions were unstable to gravitational separation. At low SORs (0.1 and 0.5), emulsions produced with phospholipids had a smaller particle diameter than those produced with a synthetic surfactant (Tween 80), but at a higher SOR (1.0), this trend was reversed. High-energy methods (microfluidization and sonication) formed significantly smaller droplets (d < 10 μm) than spontaneous emulsification. The results from this study show that low-energy methods could be utilized with natural surfactants for applications for which fine droplets are not essential.

  7. Patterned gradient surface for spontaneous droplet transportation and water collection: simulation and experiment

    International Nuclear Information System (INIS)

    Tan, Xianhua; Zhu, Yiying; Shi, Tielin; Tang, Zirong; Liao, Guanglan

    2016-01-01

    We demonstrate spontaneous droplet transportation and water collection on wedge-shaped gradient surfaces consisting of alternating hydrophilic and hydrophobic regions. Droplets on the surfaces are modeled and simulated to analyze the Gibbs free energy and free energy gradient distributions. Big half-apex angle and great wettability difference result in considerable free energy gradient, corresponding to large driving force for spontaneous droplet transportation, thus causing the droplets to move towards the open end of the wedge-shaped hydrophilic regions, where the Gibbs free energy is low. Gradient surfaces are then fabricated and tested. Filmwise condensation begins on the hydrophilic regions, forming wedge-shaped tracks for water collection. Dropwise condensation occurs on the hydrophobic regions, where the droplet size distribution and departure diameters are controlled by the width of the regions. Condensate water from both the hydrophilic and hydrophobic regions are collected directionally to the open end of the wedge-shaped hydrophilic regions, agreeing with the simulations. Directional droplet transport and controllable departure diameters make the branched gradient surfaces more efficient than smooth surfaces for water collection, which proves that gradient surfaces are potential in water collection, microfluidic devices, anti-fogging and self-cleaning. (paper)

  8. Visualization and simulation of imbibition in the matrix-fracture system

    Energy Technology Data Exchange (ETDEWEB)

    Haghighi, M.; Shariat-Panahi, F. [Tehran Univ., (Iran, Islamic Republic of); Yortsos, Y.C. [Southern California Univ., CA (United States)

    2005-07-01

    In order to realistically predict ultimate oil recovery from naturally fractured reservoirs during water displacement, it is important to understand the flow behavior in the matrix-fracture systems at pore level. This study assessed some unclear theories that have been put forward regarding the production behavior of fractured oil reservoirs with water drive or during water injection. Primary imbibition at the pore level was visualized during 2 series of experiments, one without the effects of gravity at various capillary number values (Nc) and mobility ratios (M), and another with the effects of gravity at different Nc and constant M. In the experiments without gravity effects, it was observed that at low Nc the wetting fluid preferentially invaded the matrix. A critical capillary number was identified for the start of penetration in the fracture when the viscosity ratio was much less than one, and another was identified for the rate of propagation of the front in the fracture. The critical capillary numbers were in agreement with the results of a pore network simulation. Free imbibition in a fractured system was also examined and compared favorably with pore network simulation. All experiments under gravity effects were performed on 3 types of micromodels with different fracture orientations and gravity effects. The amount of oil recovery from the matrix fracture systems at various capillary numbers was determined and the results were compared with the model with no fracture. The results indicate that the amount of oil recovery by water displacement under the water-wet condition of the model is not very sensitive to the orientation of fractures. 21 refs., 3 tabs., 16 figs.

  9. Mechanical dispersion of clay from soil into water: readily-dispersed and spontaneously-dispersed clay

    Science.gov (United States)

    Czyż, Ewa A.; Dexter, Anthony R.

    2015-01-01

    A method for the experimental determination of the amount of clay dispersed from soil into water is described. The method was evaluated using soil samples from agricultural fields in 18 locations in Poland. Soil particle size distributions, contents of organic matter and exchangeable cations were measured by standard methods. Sub-samples were placed in distilled water and were subjected to four different energy inputs obtained by different numbers of inversions (end-over-end movements). The amounts of clay that dispersed into suspension were measured by light scattering (turbidimetry). An empirical equation was developed that provided an approximate fit to the experimental data for turbidity as a function of number of inversions. It is suggested that extrapolation of the fitted equation to zero inversions enables the amount of spontaneously-dispersed clay to be estimated. This method introduces the possibility of replacing the existing subjective, qualitative method of determining spontaneously-dispersed clay with a quantitative, objective method. Even though the dispersed clay is measured under saturated conditions, soil samples retain a `memory' of the water contents at which they have been stored.

  10. Thermodynamic insight into spontaneous hydration and rapid water permeation in aquaporins

    Energy Technology Data Exchange (ETDEWEB)

    Barati Farimani, A.; Aluru, N. R. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Tajkhorshid, Emad [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Biochemistry and Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2014-08-25

    We report here a detailed thermodynamic description of water molecules inside a biological water channel. Taking advantage of high-resolution molecular dynamics trajectories calculated for an aquaporin (AQP) channel, we compute the spatial translational and rotational components of water diffusion and entropy in AQP. Our results reveal that the spontaneous filling and entry of water into the pore in AQPs are driven by an entropic gain. Specifically, water molecules exhibit an elevated degree of rotational motion inside the pore, while their translational motion is slow compared with bulk. The partial charges of the lining asparagine residues at the conserved signature Asn-Pro-Ala motifs play a key role in enhancing rotational diffusion and facilitating dipole flipping of water inside the pore. The frequencies of the translational and rotational motions in the power spectra overlap indicating a strong coupling of these motions in AQPs. A shooting mechanism with diffusive behavior is observed in the extracellular region which might be a key factor in the fast conduction of water in AQPs.

  11. Spontaneous self-coating of a water drop by flaky copper powders: critical role of the particle shape.

    Science.gov (United States)

    Chang, Cheng-Chung; Wu, Cyuan-Jhang; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2015-06-14

    The self-coating process of solid particles over a liquid drop is important for the formation of a liquid marble. Generally, some external forces such as rolling or flipping are used to cover a drop by small particles. In this work, it is observed that flaky copper powders can spontaneously spread over the planar water surface and form a dense flat cluster with a fractal dimension of 2. Moreover, flaky copper powders can cover the water pendant and sessile drops spontaneously and rapidly. This powder-coated drop can roll on an inclined plane at a relatively high speed. However, spontaneous self-coating disappears for spheroidal copper powders. To explain our observations, the shape factors of particles are introduced into the spreading coefficient S for powders on the liquid surface. The flaky powders have the lowest shape factors and therefore spontaneous self-coating formation, with S > 0.

  12. Cold-induced imbibition damage of lettuce embryos: A study using cryo-scanning electron microscopy

    NARCIS (Netherlands)

    Nijsse, J.; Walther, P.; Hoekstra, F.

    2004-01-01

    The impact of rehydration on a multicellular organism was studied in lettuce (Lactuca sativa L.) embryos, using cryo-scanning electron microscopy (cryo-SEM). Naked embryos were sensitive to imbibitional stress, whereas embryos with an intact, thick-walled endosperm were not. Imbibitional injury to

  13. Expression profile of maize (Zea mays) scutellar epithelium during imbibition.

    Science.gov (United States)

    Tnani, Hedia; García-Muniz, Nora; Vicient, Carlos M; López-Ribera, Ignacio

    2012-09-15

    The scutellum is a shield-shaped structure surrounding the embryo axis in grass species. The scutellar epithelium (Sep) is a monolayer of cells in contact with the endosperm. The Sep plays an important role during seed germination in the secretion of gibberellins and hydrolytic enzymes and in the transport of the hydrolized products to the growing embryo. We identified 30 genes predominantly expressed after imbibition in the Sep as compared to other parts of the scutellum. A high proportion of these genes is involved in metabolic processes. Some other identified genes are involved in the synthesis or modification of cell walls, which may be reflected in the changes of cell shape and cell wall composition that can be observed during imbibition. One of the genes encodes a proteinase that belongs to a proteinase family typical of carnivorous plants. Almost nothing is known about their role in other plants or organs, but the scutellar presence may point to a "digestive" function during germination. Genes involved in the production of energy and the transport of peptides were also identified. Copyright © 2012 Elsevier GmbH. All rights reserved.

  14. A Dynamic Pore-Scale Model of Imbibition

    DEFF Research Database (Denmark)

    Mogensen, Kristian; Stenby, Erling Halfdan

    1998-01-01

    We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis of the a......We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis...... of the above-mentioned parameters, except the viscosity ratio. We find that contact angle, aspect ratio and capillary number all have a significant influence on the competition between piston-like advance, leading to high recovery, and snap-off, causing oil entrapment. Due to enormous CPU-time requirements we...... been entirely inhibited, in agreement with results obtained by Blunt using a quasi-static model. For higher aspect ratios, the effect of rate and contact angle is more pronounced. Many core floods are conducted at capillary numbers in the range 10 to10.6. We believe that the excellent recoveries...

  15. Temperature measurement of single evaporating water droplets in a nitrogen flow using spontaneous Raman scattering.

    Science.gov (United States)

    Heinisch, Christian; Wills, Jon B; Reid, Jonathan P; Tschudi, Theo; Tropea, Cameron

    2009-11-14

    The evaporation dynamics of stationary water droplets held within an electrodynamic trap are investigated in a nitrogen flow of variable velocity. In particular, the influence of the nitrogen gas flow on the temperature of the evaporating water droplets is studied. By applying a contact free measurement technique, based on spontaneous Raman scattering, time averaged and time resolved measurements of temperature in the droplet volume are compared. This technique determines the temperature from an intensity ratio in the OH stretching band of the Stokes-Raman scattering after calibration. The measured trends in temperature over the first 5 s of evaporation are found to be in agreement with theoretical calculations of the heat and mass transfer rates.

  16. Captive bottlenose dolphins (Tursiops truncatus spontaneously using water flow to manipulate objects.

    Directory of Open Access Journals (Sweden)

    Chisato Yamamoto

    Full Text Available Several terrestrial animals and delphinids manipulate objects in a tactile manner, using parts of their bodies, such as their mouths or hands. In this paper, we report that bottlenose dolphins (Tursiops truncatus manipulate objects not by direct bodily contact, but by spontaneous water flow. Three of four dolphins at Suma Aqualife Park performed object manipulation with food. The typical sequence of object manipulation consisted of a three step procedure. First, the dolphins released the object from the sides of their mouths while assuming a head-down posture near the floor. They then manipulated the object around their mouths and caught it. Finally, they ceased to engage in their head-down posture and started to swim. When the dolphins moved the object, they used the water current in the pool or moved their head. These results showed that dolphins manipulate objects using movements that do not directly involve contact between a body part and the object. In the event the dolphins dropped the object on the floor, they lifted it by making water flow in one of three methods: opening and closing their mouths repeatedly, moving their heads lengthwise, or making circular head motions. This result suggests that bottlenose dolphins spontaneously change their environment to manipulate objects. The reason why aquatic animals like dolphins do object manipulation by changing their environment but terrestrial animals do not may be that the viscosity of the aquatic environment is much higher than it is in terrestrial environments. This is the first report thus far of any non-human mammal engaging in object manipulation using several methods to change their environment.

  17. Effects of gravity and inlet/outlet location on a two-phase cocurrent imbibition in porous media

    KAUST Repository

    El-Amin, Mohamed

    2011-01-01

    We introduce 2D numerical investigations of the problem of gravity and inlet/outlet location effects of water-oil two-phase cocurrent imbibition in a porous medium. Three different cases of side-, top-, and bottom-inlet location are considered. Two-dimensional computations are carried out using the finite element method. Intensive comparisons are done between considering and neglecting gravity effect on water saturation, pressures of water and oil as well as water velocity. Results are introduced either in curves or as 2D visualization graphs. The results indicate that the buoyancy effects due to gravity force take place depending on inlet location. So, the buoyancy force in the momentum equations of the co-current imbibition model cannot be neglected as done by several previous studies. Also, we note that the 2D zero gravity model has a uniform flow and may be represented as 1D flow unlike the 2D nonzero gravity model showing a nonuniform flow. Copyright 2011 M. F. El-Amin and Shuyu Sun.

  18. Water Buffalo (Bubalus bubalis) as a spontaneous animal model of Vitiligo.

    Science.gov (United States)

    Singh, Vijay Pal; Motiani, Rajender K; Singh, Archana; Malik, Garima; Aggarwal, Rangoli; Pratap, Kunal; Wani, Mohan R; Gokhale, Suresh B; Natarajan, Vivek T; Gokhale, Rajesh S

    2016-07-01

    Vitiligo is a multifactorial acquired depigmenting disorder. Recent insights into the molecular mechanisms driving the gradual destruction of melanocytes in vitiligo will likely lead to the discovery of novel therapies, which need to be evaluated in animal models that closely recapitulate the pathogenesis of human vitiligo. In humans, vitiligo is characterized by a spontaneous loss of functional melanocytes from the epidermis, but most animal models of vitiligo are either inducible or genetically programmed. Here, we report that acquired depigmentation in water buffalo recapitulates molecular, histological, immunohistochemical, and ultrastructural changes observed in human vitiligo and hence could be used as a model to study vitiligo pathogenesis and facilitate the discovery and evaluation of therapeutic interventions for vitiligo. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Rethinking historical and cultural source of spontaneous mental models of water cycle: in the perspective of South Korea

    Science.gov (United States)

    Nam, Younkyeong

    2012-06-01

    This review explores Ben-Zvi Assaraf, Eshach, Orion, and Alamour's paper titled "Cultural Differences and Students' Spontaneous Models of the Water Cycle: A Case Study of Jewish and Bedouin Children in Israel" by examining how the authors use the concept of spontaneous mental models to explain cultural knowledge source of Bedouin children's mental model of water compared to Jewish children's mental model of water in nature. My response to Ben-Zvi Assaraf et al.'s work expands upon their explanations of the Bedouin children's cultural knowledge source. Bedouin children's mental model is based on their culture, religion, place of living and everyday life practices related to water. I suggest a different knowledge source for spontaneous mental model of water in nature based on unique history and traditions of South Korea where people think of water in nature in different ways. This forum also addresses how western science dominates South Korean science curriculum and ways of assessing students' conceptual understanding of scientific concepts. Additionally I argue that western science curriculum models could diminish Korean students' understanding of natural world which are based on Korean cultural ways of thinking about the natural world. Finally, I also suggest two different ways of considering this unique knowledge source for a more culturally relevant teaching Earth system education.

  20. Modeling of non-equilibrium effects in solvent-enhanced spontaneous imbibition in fractured reservoirs

    NARCIS (Netherlands)

    Chahardowli, M.; Bruining, J.

    2013-01-01

    In fractured reservoirs, much of the oil is stored in low permeable matrix blocks that are surrounded by a high permeability fracture network. Therefore, production from fractured reservoir depends on the transfer between fracture and matrix, which is critically dependent on their interaction.

  1. Photoelectrochemical water splitting and hydrogen generation by a spontaneously formed InGaN nanowall network

    Energy Technology Data Exchange (ETDEWEB)

    Alvi, N. H., E-mail: nhalvi@isom.upm.es, E-mail: r.noetzel@isom.upm.es; Soto Rodriguez, P. E. D.; Kumar, Praveen; Gómez, V. J.; Aseev, P.; Nötzel, R., E-mail: nhalvi@isom.upm.es, E-mail: r.noetzel@isom.upm.es [ISOM Institute for Systems Based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Alvi, A. H. [Department of Physics, Government College University, Faisalabad (Pakistan); Alvi, M. A. [Department of Chemistry, Government College University, Faisalabad (Pakistan); Willander, M. [Department of Science and Technology (ITN), Campus Norrköping, Linköping University, 60174 Norrköping (Sweden)

    2014-06-02

    We investigate photoelectrochemical water splitting by a spontaneously formed In-rich InGaN nanowall network, combining the material of choice with the advantages of surface texturing for light harvesting by light scattering. The current density for the InGaN-nanowalls-photoelectrode at zero voltage versus the Ag/AgCl reference electrode is 3.4 mA cm{sup −2} with an incident-photon-to-current-conversion efficiency (IPCE) of 16% under 350 nm laser illumination with 0.075 W·cm{sup −2} power density. In comparison, the current density for a planar InGaN-layer-photoelectrode is 2 mA cm{sup −2} with IPCE of 9% at zero voltage versus the Ag/AgCl reference electrode. The H{sub 2} generation rates at zero externally applied voltage versus the Pt counter electrode per illuminated area are 2.8 and 1.61 μmol·h{sup −1}·cm{sup −2} for the InGaN nanowalls and InGaN layer, respectively, revealing ∼57% enhancement for the nanowalls.

  2. Imaging of forced-imbibition in carbonate rocks using synchrotron X-ray micro-tomography

    Science.gov (United States)

    Singh, K.; Menke, H. P.; Andrew, M. G.; Lin, Q.; Saif, T.; Al-Khulaifi, Y.; Reynolds, C. A.; Bijeljic, B.; Rau, C.; Blunt, M. J.

    2016-12-01

    We have investigated the pore-scale behavior of brine-oil systems and oil trapping during forced-imbibition in a water-wet carbonate rock in a capillary-dominated flow regime at reservoir pressure conditions. To capture the dynamics of the brine-oil front progression and snap-off process, real-time tomograms with a time resolution of 38 s (24 s for imaging and 14 s for recording the data) and a spatial resolution of 3.28 µm were acquired at Diamond Light Source (UK). The data were first analyzed at global scale (complete imaged rock) for overall front behavior. From the saturation profiles, we obtain the location of the tail of the desaturation front that progresses with a velocity of 13 µm/min. This velocity is smaller than average flow velocity 16.88 µm/min, which explains why it needs slightly more than 1 pore volume of brine injection to reach the residual saturation of oil in a water-wet rock. The data were further analyzed at local scale to investigate the pore-scale mechanisms of oil trapping during brine flooding. We isolated various trapping events which resulted in the creation of discrete oil ganglia occupying one to several pore bodies. We perform pore-scale curvature analysis of brine-oil interfaces to obtain local capillary pressure that will be related to the shape and the size of throats in which ganglia were trapped.

  3. Development of combined imbibition and hydrothermal threshold models to simulate maize (Zea mays) and chickpea (Cicer arietinum) seed germination in variable environments.

    Science.gov (United States)

    Finch-Savage, W E; Rowse, H R; Dent, K C

    2005-03-01

    * The ability of hydrothermal time (HTT) and virtual osmotic potential (VOP) models to describe the kinetics of maize (Zea mays) and chickpea (Cicer arietinum) seed germination under variable conditions of water potential was investigated with a view to gaining an improved understanding of the impact of on-farm seed priming on seedling establishment through simulation. * Germination and/or imbibition time courses were recorded over a wide range of constant temperatures and water potentials and simple stepwise changes in water potential. * Both models adequately described germination under constant environmental conditions, but not conditions of water potential that varied. To test the hypothesis that this inaccuracy resulted from the use of ambient water potential, a parsimonious model of seed imbibition was developed to calibrate the HTT and VOP models (IHTT and IVOP) and drive them with estimates of seed water potential. * The IHTT and IVOP models described germination during stepwise changes in water potential more accurately than the conventional models, and should contribute to improved predictions of germination time in the field.

  4. Spontaneous and Fast Growth of Large‐Area Graphene Nanofilms Facilitated by Oil/Water Interfaces

    DEFF Research Database (Denmark)

    Gan, Shiyu; Zhong, Lijie; Wu, Tongshun

    2012-01-01

    An efficient wet-chemical method based on soft interfacial self-assembly is developed for spontaneous, fast growth of large-area graphene nanofilms on various substrates. The graphene nanofilms produced show tunable optical properties and a highly reversible optoelectronic response. Complementary...... to chemical vapor deposition, this method could offer a fast, simple, and low-cost chemical strategy to produce graphene nanofilms....

  5. From the Pore to the Laboratory Scale: Predicting Flow Behavior for Drainage and Imbibition in Heterogeneous Porous Media

    Science.gov (United States)

    Papafotiou, A.; Neuweiler, I.; Helmig, R.; Schaap, J.; Kaestner, A.; Lehmann, P.; Flühler, H.; Hassanein, R.; Ahrenholz, B.; Tölke, J.; Peters, A.; Durner, W.

    2008-12-01

    The presented work focuses on the comparison of predictions of two-phase drainage and imbibition in heterogeneous porous media to an experimentally measured hysteretic flow process, using hydraulic properties determined on the one hand on the pore scale and on the other hand on the lab scale. For that purpose, a well controlled 3-D experiment with pre-defined block heterogeneities is conducted, where neutron tomography is used to map 3-D water distribution after successive drainage and imbibition steps. The material and hydraulic properties of the two sands are first measured in the laboratory with multistep outflow/inflow experiments. Additionally, the pore structure of the sands is acquired by means of image analysis of synchrotron tomography data and the structure is used for pore-scale simulation of one- and two-phase flow with lattice Boltzmann methods. This provides two sets of material and hydraulic properties of the sands, the second one derived from the detailed pore structure. The two sets of hydraulic properties, including hysteretic capillary pressure-saturation relationships, are then used in numerical simulations of the 3-D experiment. Hysteresis in the numerical model is combined with a capillary interface condition for the treatment of material interfaces and the approximation of saturation discontinuities due to heterogeneities. We discuss possibilities as well as difficulties and limitations in the determination of hydraulic properties of materials using two conceptually different approaches (pore scale and lab scale). We then test with the numerical simulations how good can predictions be on hysteretic two-phase flow and water content in structured media, when using these state-of-the-art methods for the determination of hydraulic properties. Based on the numerical simulations, we discuss the sensitivity in the hydraulic properties determined on different scales, the influence of material interfaces in structured heterogeneities and finally the

  6. Effects of gravity and inlet location on a two-phase countercurrent imbibition in porous media

    KAUST Repository

    El-Amin, Mohamed

    2012-01-01

    We introduce a numerical investigation of the effect of gravity on the problem of two-phase countercurrent imbibition in porous media. We consider three cases of inlet location, namely, from, side, top, and bottom. A 2D rectangular domain is considered for numerical simulation. The results indicate that gravity has a significant effect depending on open-boundary location.

  7. Novel Application of the Flotation Technique To Measure the Wettability Changes by Ionically Modified Water for Improved Oil Recovery in Carbonates

    DEFF Research Database (Denmark)

    Sohal, Muhammad Adeel Nassar; Thyne, Geoffrey; Søgaard, Erik Gydesen

    2016-01-01

    the wettability, we need to understand the initial wetting conditions and design an ionically modified water (advanced water) to alter wettability and improve oil recovery. If a reservoir has already been reached to the optimum wetting conditions by injecting formation water or any other fluid......The accurate determination of the wetting condition of carbonate reservoirs is a prerequisite for the selection of any enhanced oil recovery (EOR) fluid. Most carbonate formations are initially oil-wet to intermediate-wet at reservoir conditions. In order to correctly chose an EOR fluid to alter......, then there is no need for ionically modified water. A number of methods have been devised to identify the wetting conditions including contact angle measurements, spontaneous imbibition, and chromatographic separation, etc. But contact angle measurement requires surfaces that lack natural surface roughness, spontaneous...

  8. Rhodiola-water extract induces β-endorphin secretion to lower blood pressure in spontaneously hypertensive rats.

    Science.gov (United States)

    Lee, Wei-Jing; Chung, Hsien-Hui; Cheng, Yung-Ze; Lin, Hung Jung; Cheng, Juei-Tang

    2013-10-01

    Rhodiola rosea (Rhodiola) is grown at high altitudes and northern latitudes. It is mainly used clinically as an adaptogen, but antihypertensive effects have been reported for the extract. These have not been well investigated, so in the present study, we evaluated the effect of Rhodiola-water extract on blood pressure in spontaneously hypertensive rats (SHRs) and investigated the potential mechanism(s) for this action. In conscious male SHRs, systolic blood pressure (SBP) and heart rate were recorded using the tail-cuff method. Plasma β-endorphin was measured by enzyme-linked immunosorbent assay. Rhodiola-water extract decreased SBP in SHRs in a dose-dependent manner, and this action was more significant than that in normal group named Wistar-Kyoto (WKY) rats. This reduction of SBP in SHRs was inhibited by pretreatment with the selective opioid μ-receptor antagonist, cyprodime, but not by naloxonazine, an antagonist specific to opioid μ1-receptor. Also, the SBP-lowering action of Rhodiola-water extract was attenuated in adrenalectomized SHRs. Moreover, Rhodiola-water extract dose-dependently increased β-endorphin release in SHRs, and the elevation of β-endorphin in SHRs was higher than that in WKY. Thus, we suggest that Rhodiola-water extract can induce release of β-endorphin to lower SBP in SHRs. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Effect of lead on imbibition, germination, and growth of Phaseolus vulgaris L. and Zea mays L.

    Directory of Open Access Journals (Sweden)

    Gustavo Isaza Guzmán Isaza Guzmán

    2013-07-01

    Full Text Available Lead is highly reactive and it can be consequently toxic to living cells to both plants and humans. This heavy metal is a source of contamination to the environment and it disrupts natural cycles. The present study was aimed to evaluate the effect of lead on the imbibition process, germination and growth in the bean (Phaseolus vulgaris L. and maize (Zea mays L.. It was developed a system consisting of receptacles to expose flooded plants at different concentrations of the metal. Results showed that at concentrations of 5 g l-1 lead imbibition process was affected, but was more evident in bean. Germination percentage was not affected in maize seeds, while viability was affected in bean seeds. We observed statistically that there is an effect on organ growth of root, stem and leaf in both species in the presence of solution whose effect is most noticeable in bean plants. Key words: heavy metals,phytoremediation, stress, toxic substances

  10. Spontaneous assembly of HSP90 inhibitors at water/octanol interface: A molecular dynamics simulation study

    Science.gov (United States)

    Zolghadr, Amin Reza; Boroomand, Samaneh

    2017-02-01

    Drug absorption at an acceptable dose depends on the pair of solubility and permeability. There are many potent therapeutics that are not active in vivo, presumably due to the lack of capability to cross the cell membrane. Molecular dynamics simulation of radicicol, diol-radicicol, cyclopropane-radicicol and 17-DMAG were performed at water/octanol interface to suggest interfacial activity as a physico-chemical characteristic of these heat shock protein 90 (HSP90) inhibitors. We have observed that orally active HSP90 inhibitors form aggregates at the water/octanol and DPPC-lipid/water interfaces by starting from an initial configuration with HSP90 inhibitors embedded in the water matrix.

  11. Vapor Pressure Plus: An Experiment for Studying Phase Equilibria in Water, with Observation of Supercooling, Spontaneous Freezing, and the Triple Point

    Science.gov (United States)

    Tellinghuisen, Joel

    2010-01-01

    Liquid-vapor, solid-vapor, and solid-liquid-vapor equilibria are studied for the pure substance water, using modern equipment that includes specially fabricated glass cells. Samples are evaporatively frozen initially, during which they typically supercool to -5 to -10 [degrees]C before spontaneously freezing. Vacuum pumping lowers the temperature…

  12. Experimental study on imbibition displacement mechanisms of two-phase fluid using micromodel: Fracture network, distribution of pore size, and matrix construction

    Science.gov (United States)

    Jafari, Iman; Masihi, Mohsen; Nasiri Zarandi, Masoud

    2017-12-01

    In this study, the effect of different parameters on the fluid transport in a fractured micromodel has been investigated. All experiments in this study have been conducted in a glass micromodel. Since the state of wetting is important in the micromodel, the wetting experiments have been conducted to determine the state of wetting in the micromodel. The used micromodel was wet by water and non-wet regarding normal decane. The fracture network, distribution of pore size, matrix construction, and injection rate are the most important parameters affecting the process. Therefore, the influence of these parameters was studied using five different patterns (A to E). The obtained results from pattern A showed that increasing water injection the flow rate results in both higher rate of imbibition and higher ultimate recovery. Pattern B, which was characterized with higher porosity and permeability, was employed to study the effect of matrix pore size distribution on the imbibition process. Compared to pattern A, a higher normal decane production was observed in this pattern. Patterns C and D were designed to understand the impact of lateral fractures on the displacement process. Higher ultimate recoveries were obtained in these patterns. A system of matrix-fracture was designed (pattern E) to evaluate water injection performance in a multi-block system. Injection of water with the flow rate of 0.01 cc/min could produce 15% of the oil available in the system. While in the test with the flow rate of 0.1 cc/min, a normal decane recovery of 0.28 was achieved.

  13. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  14. A Dynamic Two-Phase Pore-Scale Model of Imbibition

    DEFF Research Database (Denmark)

    Mogensen, Kristian; Stenby, Erling Halfdan

    1998-01-01

    We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle, and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis...... of the above-mentioned parameters, except from the viscosity ratio. We find that contact angle, aspect ratio, and capillary number all have a significant influence on the competition between piston-lice advance, leading to high recovery, and snap-off, causing oil entrapment. Due to significant CPU...

  15. Sessile drops imbibition over nano porous substrates : application for art painting restoration

    Science.gov (United States)

    Léang, Marguerite; Pauchard, Ludovic; Lee, Lay-Theng; Ott, Frédéric; Giorgiutti-Dauphiné, Frédérique

    2016-11-01

    Art painting restoration aims to restore and preserve the integrity of a painting. Most of the techniques consist of depositing solvents on the surface of the painting to dissolve the varnish layer. However the sublayers can be damaged by the penetration of the solvent, possibly resulting in swelling or cracking processes. Due to the physical and chemical complexity of the pictorial layer, we propose to study solvent penetration in model nano porous media obtained by controlled drying of aqueous dispersions of silica nanoparticles. We present the dynamics of imbibition of sessile solvent drops on porous media with different pore sizes. Three different regimes in the evolution of the drop size with time are identified. Our experimental set-up provides a precise direct quantification of the different flows outside and through the porous media. Different experimental techniques are used to characterize the porous media : neutron imaging to determine the permeability and microindentation testing to estimate the mechanical properties of the media after the imbibition process. Supported by PALM LabEx Grant.

  16. Etude fondamentale de l'imbibition dans un réservoir fissuré Basic Research on Inbibition in a Fractured Reservoir

    Directory of Open Access Journals (Sweden)

    Iffly R.

    2006-11-01

    efficiency in a fractured reservoir closely depends on the magnitude and rate of water imbibition within the matrix blocks. The effects of both block height and permeability on cil recovery as well as those of block boundary conditions (fractures may contain either water or oil, or may be tight have been determined through numerous laboratory experiments with actual rock and fluid samples from a field operated by Elf.

  17. Visualization and Analysis of Multiple Fluid Phases in Sandstone for Drainage and Imbibition

    Science.gov (United States)

    Chen, D.; Pyrak-Nolte, L.

    2003-12-01

    In this study, we present results on the measurements of interfacial area per volume (IAV) in a natural three-dimensional porous medium, i.e. sandstone. A set of cored sandstone samples measuring 52 mm in diameter by 100 mm or 25mm in length were used in Wood's metal injection experiments to determine IAV. A wood's metal injection method was used to solidify the non-wetting fluid, which is the metal, and ethylene glycol was used to represent a wetting phase fluid. These samples were injected under different pressures from 0.014 MPa to 0.68MPa. Ethylene glycol flow rates measurements were applied before and after the injections to find the permeability difference of the samples. To visualize different phases and determine the IAV for a sample injected with Wood's metal, images of the Wood's-metal-injected core were taken with a Scanning Electron Microscope (SEM). A custom computer code was used to analyze each SEM image to isolate the rock phase, the wetting phase (EG) and the non-wetting phase, and to calculate the interface between each two phases. Analysis of the images of the metal-injected sample of the imbibitions processes found that average interfacial length per area (ILA) values for a natural three-dimensional system (i.e., sandstone) range from 4 to 150 per cm for the rock-metal interface and 20 to 480 per cm for the EG-rock interface, for pressures that range from 0.0134 MPa to 0.68 MPa. For the metal-EG interface, ILA values rang from 0.4 to 2.5 per cm for the same pressure range. Analysis of the images of the metal-injected sample of the drainages processes found that average ILA values of sandstone samples range from 80 to 120 per cm for the rock-metal interface and from 120 to 170 per cm for the EG-rock interface, for pressures that range from 0.0134 MPa to 0.68 MPa. For the metal-EG interface, ILA values ranged from 0.4 to 3.0 per cm for the same pressure range. The investigation also found a break though pressure for imbibition process between 0

  18. Simulating drainage and imbibition experiments in a high-porosity micromodel using an unstructured pore network model

    NARCIS (Netherlands)

    Joekar Niasar, V.; Hassanizadeh, S.M.; Pyrak-Nolte, L.J.; Berentsen, C.W.J.

    2009-01-01

    Development of pore network models based on detailed topological data of the pore space is essential for predicting multiphase flow in porous media. In this work, an unstructured pore network model has been developed to simulate a set of drainage and imbibition laboratory experiments performed on a

  19. Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

    Directory of Open Access Journals (Sweden)

    Nascimento Warley Marcos

    2003-01-01

    Full Text Available Lettuce (Lactuca sativa L. seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB were incubated at temperatures ranging from 15degrees to 35degreesC at light and dark conditions. Other seeds were imbibed in dark at 20degrees; 25degrees; 30degrees; and 35degreesC for 8 and 16 hours and then transferred to 20 or 35degreesC, in dark. Seeds were also incubated at constant temperature of 20degrees and 35 degreesC, in the dark, as control. In another treatment, seeds were primed for 3 days at 15degreesC with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25degreesC. Seeds incubated at 20degreesC had 97% germination, whereas seeds incubated at 35degreesC did not germinate. Seeds imbibed at 20degreesC for 8 and 16 hours had germination. At 35degreesC, seeds imbibed initially at 20degreesC for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25degreesC for 16 hours, germinated satisfactory at 35degreesC. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20degreesC. Primed seeds had 100% germination at 35degreesC, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

  20. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  1. Effects of a hot-water extract of porcini (Boletus aestivalis) mushrooms on the blood pressure and heart rate of spontaneously hypertensive rats.

    Science.gov (United States)

    Midoh, Naoki; Miyazawa, Noriko; Eguchi, Fumio

    2013-01-01

    The repeated once-daily oral administration of a hot-water extract of porcini, Boletus aestivalis, mushrooms (WEP) to spontaneously hypertensive rats (SHR) for 18 weeks decreased the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate. The WEP administration also decreased blood urea nitrogen (BUN), creatinine (Cre), and triglyceride (TG), and increased high-density lipoprotein-cholesterol (HDL-C) in the blood, suggesting that WEP improved the status of hypertension, as well as the high heart rate and metabolic abnormalities involved in hypertension.

  2. WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

    2003-02-01

    The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying

  3. Evaluation of uncertainty and detection limits in 210Pb and 210Po measurement in water by alpha spectrometry using 210Po spontaneous deposition onto a silver disk

    International Nuclear Information System (INIS)

    Fernández, Pedro L.; Gómez, José; Ródenas, Carmen

    2012-01-01

    An easy and accurate method for the determination of 210 Pb and 210 Po in water using 210 Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of 210 Pb, 210 Bi and 210 Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of 210 Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between 210 Pb and 210 Bi and the second after a sufficient time for the ingrowth of 210 Po from 210 Pb to be significant. As shown, for a recommended time interval of seven months between 210 Po measurements, the applicability of the proposed method is limited to water samples with a 226 Ra to 210 Pb activity ratio C Ra /C Pb ≤4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L −1 for 210 Pb in water samples with an initial activity of 210 Po in the range 0–200 mBq L −1 , and between 0.6 and 8.5 mBq L −1 for 210 Po in water samples with an initial activity of 210 Pb in the same range. - Highlights: ► 210 Pb and 210 Po measurement in water by 210 Po spontaneous deposition onto silver disks. ► 210 Pb and 210 Po determination based on 210 Po measurement in two different aliquots. ► Evaluation of characteristic limits in radioactivity measurements using ISO 11929-7. ► 10 Pb - 210 Po detection limits decrease with time elapsed between 210 Po measurements.

  4. Running title: Water distribution in chickpea seeds

    African Journals Online (AJOL)

    agriphy20

    2012-07-24

    Jul 24, 2012 ... In plant and seed systems, at least three water components can be identified with the transverse ..... Fractional population of different water protons of varying mobilities with hours of imbibition in water at 20°C for magnetically exposed and .... reserves of the seedling during germination. In the present study ...

  5. COMBINED BIOLOGICAL-PHOTOCATALYTIC TREATMENT FOR THE MINERALIZATION OF A MIXTURE OF CHLOROPHENOLS IN AN ELECTROLYTE-CONTAINING MODEL WATER AND SPONTANEOUS SEDIMENTATION OF TITANIUM DIOXIDE

    Directory of Open Access Journals (Sweden)

    Dhanus Suryaman

    2010-06-01

    Full Text Available To shorten the biological treating time and to examine the effect of electrolytes in a model water on the photocatalytic treatment, the combined biological-photocatalytic treatment was evaluated for removal of a mixture (total: 100 mg L-1, each: 25 mg L-1 of 2-chlorophenol (2-CP, 2,4-dichlorophenol (2,4-DCP, 2,4,5-trichlorophenol (2,4,5-TCP, and pentachlorophenol (PCP in tap water. The mineralization of the four phenols was performed by a flow (biological treatment-circulative flow (photocatalytic treatment operation under black light and sunlight irradiations. After a large portion of biodegradable 2-CP and 2,4-DCP, and around half amount of slightly biodegradable 2,4,5-TCP were removed by the biological treatment, the remained three chlorophenols, biorecalcitrant PCP, and  biodegradation products were completely removed by the subsequent photocatalytic treatment. The combined treatment significantly shortened the degradation time only the biotreatment. High circulative flow rate (600 mL min-1 enabled for TiO2 particles to completely suspend in a tubular photoreactor and resulted in high removals of chlorophenols and TOC. Sunlight irradiation was successfully used and the saving of the electric energy of black light was possible. Since TiO2 particles in the tap water spontaneously sedimented on standing after the photocatalytic treatment, the combined system can be operated by integrating it with the TiO2 separation.   Keywords: photocatalysis, titanium dioxide, biodegradation, pollutant, wastewater

  6. Single-Site Active Cobalt-Based Photocatalyst with a Long Carrier Lifetime for Spontaneous Overall Water Splitting.

    Science.gov (United States)

    Liu, Wei; Cao, Linlin; Cheng, Weiren; Cao, Yuanjie; Liu, Xiaokang; Zhang, Wei; Mou, Xiaoli; Jin, Lili; Zheng, Xusheng; Che, Wei; Liu, Qinghua; Yao, Tao; Wei, Shiqiang

    2017-08-01

    An active and stable photocatalyst to directly split water is desirable for solar-energy conversion. However, it is difficult to accomplish overall water splitting without sacrificial electron donors. Herein, we demonstrate a strategy via constructing a single site to simultaneously promote charge separation and catalytic activity for robust overall water splitting. A single Co 1 -P 4 site confined on g-C 3 N 4 nanosheets was prepared by a facile phosphidation method, and identified by electron microscopy and X-ray absorption spectroscopy. This coordinatively unsaturated Co site can effectively suppress charge recombination and prolong carrier lifetime by about 20 times relative to pristine g-C 3 N 4 , and boost water molecular adsorption and activation for oxygen evolution. This single-site photocatalyst exhibits steady and high water splitting activity with H 2 evolution rate up to 410.3 μmol h -1  g -1 , and quantum efficiency as high as 2.2 % at 500 nm. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Imbibition and percentage of germination of cape gooseberry (Physalis peruviana L. seeds under NaCl stress

    Directory of Open Access Journals (Sweden)

    Miranda Diego

    2010-04-01

    Full Text Available

    In Colombia cape gooseberry is often grown on salt affected soils. The present study evaluated the effect of increasing NaCl concentrations on imbibition and percentage of germination of ‘Colombia’ ecotype cape gooseberry seeds. Under controlled laboratory conditions (25/20°C day/night temperature, 80% relative humidity, and a 12 hour photoperiod, the seeds were subjected to 0, 30, 60, 90 and 120 mM NaCl concentrations (corresponding to respective electrical conductivity levels of 0.8, 3.0, 6.0, 9.0, and 12.2 dS m-1, during an evaluation period of 299 hours. A significantly lower imbibition level, expressed as 35% of the fresh weight accumulated by the control seeds, was observed in the 120 mM NaCl treatment. At the end of the experiment, respective germination percentages of 97.6% and 96.4% were recorded in the salt-free seeds and in those exposed to 30 mM NaCl. In contrast, only 62.5% of those seeds treated with 120 mM NaCl germinated. Root malformations such as lack of elongation were observed in the highest NaCl concentration treatment. Regarding its germination process, cape gooseberry can be classified as moderately tolerant to sodium. In effect, after 299 h of treatment, there was no statistical difference in imbibition level or percentage of germination between the 0, 30 and 60 mM NaCl treatments.

  8. The influence of temperature in a capillary imbibition salt weathering simulation test on Mokattam limestone

    Directory of Open Access Journals (Sweden)

    Aly, N.

    2015-03-01

    Full Text Available Limestone is one of the most frequent building stones used in monuments in Egypt from ancient Egyptian times and salt weathering is one of the main threats to these monuments. During this work, cylindrical limestone samples (2 cm diameter and approx. 4 cm length from Mokattam group, one of the most frequent materials in historic Cairo, were subjected, in a purpose-made simulation chamber, to laboratory salt weathering tests with a 10% weight NaCl solution at different temperatures (20, 30, 40 °C. During each test, temperature was kept constant and salt solutions flowed continuously imbibing samples by capillary rise resembling the way they get into building stone in many real cases. Air temperature, relative humidity inside the simulation chamber and also samples weight were digitally monitored and recorded. Results show the influence of temperature and the ratio between imbibitions and evaporation on the dynamics of salt crystallization in the samples.Los monumentos egipcios se construyeron frecuentemente con caliza desde la antigüedad y uno de sus principales agentes de deterioro son las sales. Por ejemplo, en la zona histórica de El Cairo son frecuentes las calizas del grupo Mokattam. Cilindros (2 cm de diámetro y aproximadamente 4 cm de altura de esta caliza se sometieron a ensayos de deterioro por sales en una cámara experimental específicamente diseñada. Se utilizó una solución salina (10% en peso de NaCl a diferentes temperaturas (20 °C, 30 °C, 40 °C que se mantuvieron constantes en cada ensayo. La solución fluía constantemente embebiendo las muestras por capilaridad, simulando lo que ocurre en casos reales. La temperatura del aire, humedad relativa en la cámara y peso de las muestras se monitorizaron con sensores digitales. Los resultados muestran la influencia de la temperatura y del balance entre imbibición y evaporación en la dinámica de la cristalización de sales en las muestras.

  9. Effects of electrical water bath stunning current frequencies on the spontaneous electroencephalogram and somatosensory evoked potentials in hens.

    Science.gov (United States)

    Raj, A B M; O'Callaghan, M

    2004-04-01

    1. The effectiveness of water bath electrical stunning of chickens with a constant root mean square (rms) current of 100 mA per bird delivered for 3 s using 100, 200, 400, 800 and 1500 Hz sine wave alternating current (AC) was investigated in layer hens. The quantitative changes occurring in the electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) were used to determine the effectiveness of stunning. The changes occurring in the EEG were evaluated using Fast Fourier Transformations (FFT) and the SEPs were averaged to determine whether they were present or abolished. 2. The results of FFT indicated that stunning of chickens with a constant rms current of 100 mA per bird using 100 or 200 Hz induced epileptiform activity in all the hens, immediately followed by a reduction in the total (2 to 30 Hz) and relative (13 to 30 Hz) power contents in the EEG frequency bands indicative of unconsciousness and insensibility. The SEPs were abolished in the majority of hens stunned with 100 Hz and all the hens stunned with 200 Hz. 3. By contrast, stunning using 400, 800 or 1500 Hz failed to induce epileptiform activity in all the birds, the total and relative power contents in the EEG frequency bands showed a substantial increase, rather than reduction, and the SEPs were also retained in the majority of chickens. It is therefore suggested that stunning using these frequencies failed to stun them satisfactorily. In these birds, occurrence of a painful arousal, rather than unconsciousness, could not be ruled out. 4. It is therefore suggested that water bath electrical stunning of chickens with a minimum rms current of 100 mA per bird delivered using 100 or 200 Hz would be adequate to ensure bird welfare under commercial conditions, provided both the carotid arteries in the neck are severed at slaughter. On humanitarian and bird welfare grounds, a rms current of greater than 100 mA per bird should be applied whilst using frequencies of 400 Hz or more of sine wave AC

  10. Codissolution of calcium hydrogenphosphate and sodium hydrogencitrate in water. Spontaneous supersaturation of calcium citrate increasing calcium bioavailability

    DEFF Research Database (Denmark)

    Hedegaard, Martina Vavrusova; Danielsen, Bente Pia; Garcia, André Castilho

    2018-01-01

    . The supersaturated solutions had a pH around 4.7, and calcium binding to hydrogencitrate as the dominant citrate species during precipitation was found to be exothermic with a determined association constant of 357 L mol-1 at 25 °C for unit ionic strength, and δH° = -22 ± 2 kJ mol-1, δS° = -26 ± 8 J K-1 mol-1......The sparingly soluble calcium hydrogenphosphate dihydrate, co-dissolving in water during dissolution of freely soluble sodium hydrogencitrate sesquihydrate as caused by proton transfer from hydrogencitrate to hydrogenphosphate, was found to form homogenous solutions supersaturated by a factor up...... to 8 in calcium citrate tetrahydrate. A critical hydrogencitrate concentration for formation of homogeneous solutions was found to depend linearly on dissolved calcium hydrogenphosphate: [HCitr2-] = 14[CaHPO4] - 0.05 at 25 °C. The lag phase for precipitation of calcium citrate tetrahydrate...

  11. Microbiological characterization and probiotic potential of koko and koko sour water, African spontaneously fermented millet porridge and drink.

    Science.gov (United States)

    Lei, V; Jakobsen, M

    2004-01-01

    To identify and examine the diversity of predominant lactic acid bacteria (LAB) in koko and koko sour water (KSW) from different Ghanaian production sites with regard to pattern of fermentation (API 50 CHL), genotype, antimicrobial activity, and resistance to low pH and bile salts. In total 215 LAB were isolated from koko and KSW. The isolates were identified using intergenic transcribed spacers (ITS)-PCR restriction fragment length polymorphism (RFLP), API 50 CHL, restriction enzyme analysis with pulsed-field gel electrophoresis (REA-PFGE) and sequencing of the 16S rRNA gene. The dominating micro-organisms in koko was found to be Weisella confusa and Lactobacillus fermentum, followed by Lact. salivarius and Pediococcus spp. Chemometric data analysis were used to link the LAB species to the different production stages and production sites. At intra-species level the isolates were found to have a great diversity. The isolates were investigated for antimicrobial activity using agar diffusion assays, and acid and bile tolerance. Most isolates showed low levels of antimicrobial activity towards the indicator strain Listeria innocua, but not towards the bacteriocin-sensitive Lact. sakei. Growth of all LAB isolates was unaffected by the presence of 0.3% (v/v) oxgall bile. The isolates were able to survive, but were not able to grow in growth medium adjusted to pH 2.5. The dominating LAB of koko and KSW were W. confusa and Lact. fermentum showing a pronounced taxonomic biodiversity at sub-species level between stages within the production as well as between production sites. Other species observed in KSW were Lact. salivarius, Ped. pentosaceus, Ped. acidilactici and Lact. paraplantarum. They occurred in levels of 108 CFU ml-1 in fresh KSW and showed uniform antimicrobial activity, and acid and bile tolerance. The present study gives a detailed picture of the taxonomy and diversity of LAB in an African-fermented millet product that may have potential as a probiotic product

  12. Characterizing the transplanar and in-plane water transport of textiles with gravimetric and image analysis technique: Spontaneous Uptake Water Transport Tester.

    Science.gov (United States)

    Tang, K P M; Wu, Y S; Chau, K H; Kan, C W; Fan, J T

    2015-04-15

    Water absorption and transport property of textiles is important since it affects wear comfort, efficiency of treatment and functionality of product. This paper introduces an accurate and reliable measurement tester, which is based on gravimetric and image analysis technique, for characterising the transplanar and in-plane wicking property of fabrics. The uniqueness of this instrument is that it is able to directly measure the water absorption amount in real-time, monitor the direction of water transport and estimate the amount of water left on skin when sweating. Throughout the experiment, water supply is continuous which simulates profuse sweating. Testing automation could even minimise variation caused by subjective manipulation, thus enhancing testing accuracy. This instrument is versatile in terms of the fabrics could be tested. A series of shirting fabrics made by different fabric structure and yarn were investigated and the results show that the proposed method has high sensitivity in differentiating fabrics with varying geometrical differences. Fabrics with known hydrophobicity were additionally tested to examine the sensitivity of the instrument. This instrument also demonstrates the flexibility to test on high performance moisture management fabrics and these fabrics were found to have excellent transplanar and in-plane wicking properties.

  13. Characterizing the transplanar and in-plane water transport of textiles with gravimetric and image analysis technique: Spontaneous Uptake Water Transport Tester

    Science.gov (United States)

    Tang, K. P. M.; Wu, Y. S.; Chau, K. H.; Kan, C. W.; Fan, J. T.

    2015-01-01

    Water absorption and transport property of textiles is important since it affects wear comfort, efficiency of treatment and functionality of product. This paper introduces an accurate and reliable measurement tester, which is based on gravimetric and image analysis technique, for characterising the transplanar and in-plane wicking property of fabrics. The uniqueness of this instrument is that it is able to directly measure the water absorption amount in real-time, monitor the direction of water transport and estimate the amount of water left on skin when sweating. Throughout the experiment, water supply is continuous which simulates profuse sweating. Testing automation could even minimise variation caused by subjective manipulation, thus enhancing testing accuracy. This instrument is versatile in terms of the fabrics could be tested. A series of shirting fabrics made by different fabric structure and yarn were investigated and the results show that the proposed method has high sensitivity in differentiating fabrics with varying geometrical differences. Fabrics with known hydrophobicity were additionally tested to examine the sensitivity of the instrument. This instrument also demonstrates the flexibility to test on high performance moisture management fabrics and these fabrics were found to have excellent transplanar and in-plane wicking properties. PMID:25875329

  14. Highly Sprouting-Tolerant Wheat Grain Exhibits Extreme Dormancy and Cold Imbibition-Resistant Accumulation of Abscisic Acid.

    Science.gov (United States)

    Kashiwakura, Yu-ichi; Kobayashi, Daisuke; Jikumaru, Yusuke; Takebayashi, Yumiko; Nambara, Eiji; Seo, Mitsunori; Kamiya, Yuji; Kushiro, Tetsuo; Kawakami, Naoto

    2016-04-01

    Pre-harvest sprouting (PHS) of wheat (Triticum aestivum L.) grains induces hydrolyzing enzymes such as α-amylase, which considerably decreases wheat product quality. PHS occurs when cool and wet weather conditions before harvest break dormancy and induce grain germination. In this study, we used PHS-tolerant varieties, Gifu-komugi (Gifu) and OS38, to characterize the mechanisms of both dormancy breakage and dormancy maintenance at low temperatures. Physiologically mature Gifu grains exhibited dormancy after imbibition at 20°C, but germinated at 15°C. In contrast, OS38 grains remained dormant even at temperatures as low as 5°C. Embryo half-grains cut out from the dormant Gifu grains germinated by imbibition at 20°C, similar to conventional varieties worldwide. However, OS38 embryo half-grains were still dormant. Hormonome and pharmacological analyses suggested that ABA and gibberellin metabolism are important for temperature-dependent dormancy maintenance and breakage. Imbibition at 15°C decreased ABA levels but increased gibberellin levels in embryos of freshly harvested Gifu grains. Additionally, low temperatures induced expression of the ABA catabolism genes,TaABA8' OH1 and TaABA8' OH2, and the gibberellin biosynthesis gene,TaGA3ox2, in the embryos. However, in embryos of freshly harvested OS38 grains, ABA levels were increased while gibberellin levels were suppressed at 15°C. In these dormant embryos, low temperatures induced the TaNCED ABA biosynthesis genes, but suppressed TaABA8' OH2 and TaGA3ox2.These results show that the regulatory mechanism influencing the expression of ABA and gibberellin metabolism genes may be critical for dormancy maintenance and breakage at low temperatures. Our findings should help improve PHS-resistant wheat breeding programs. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  16. Role des proprietes physiques du lit de semences sur l'imbibition et la germination: I. Elaboration d'un modele du systeme "terre-graine"

    OpenAIRE

    Bruckler, Laurent

    1983-01-01

    La germination de la semence de maïs est possible lorsque celle-ci a atteint une humidité critique, en deçà de laquelle on n’observe jamais le déclenchement de la germination. La semence atteint cette humidité au cours d’une phase d’imbibition qui est sous la dépendance de la différence de potentiel existant entre la semence et le milieu extérieur. Il importe donc d’établir, au préalable, la relation potentiel/teneur en eau propre à la semence. On propose ensuite un modèle d’imbibition de...

  17. Water movement into dormant and non-dormant wheat (Triticum aestivum L.) grains.

    Science.gov (United States)

    Rathjen, Judith R; Strounina, Ekaterina V; Mares, Daryl J

    2009-01-01

    The movement of water into harvest-ripe grains of dormant and non-dormant genotypes of wheat (Triticum aestivum L.) was investigated using Magnetic Resonance Micro-Imaging (MRMI). Images of virtual sections, both longitudinal and transverse, throughout the grain were collected at intervals after the start of imbibition and used to reconstruct a picture of water location within the different grain tissues and changes over time. The observations were supplemented by the weighing measurements of water content and imbibition of grains in water containing I(2)/KI which stains starch and lipid, thereby acting as a marker for water. In closely related genotypes, with either a dormant or a non-dormant phenotype, neither the rate of increase in water content nor the pattern of water distribution within the grain was significantly different until 18 h, when germination became apparent in the non-dormant genotype. Water entered the embryo and scutellum during the very early stages of imbibition through the micropyle and by 2 h water was clearly evident in the micropyle channel. After 12 h of imbibition, embryo structures such as the coleoptile and radicle were clearly distinguished. Although water accumulated between the inner (seed coat) and outer (pericarp) layers of the coat surrounding the grain, there was no evidence for movement of water directly across the coat and into the underlying starchy endosperm.

  18. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  19. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  20. Arabidopsis Seed Mitochondria Are Bioenergetically Active Immediately upon Imbibition and Specialize via Biogenesis in Preparation for Autotrophic Growth[OPEN

    Science.gov (United States)

    Benamar, Abdelilah

    2017-01-01

    Seed germination is a vital developmental transition for production of progeny by sexual reproduction in spermatophytes. Quiescent cells in nondormant dry embryos are reawakened first by imbibition and then by perception of germination triggers. Reanimated tissues enter into a germination program requiring energy for expansion growth. However, germination requires that embryonic tissues develop to support the more energy-demanding processes of cell division and organogenesis of the new seedling. Reactivation of mitochondria to supply the required energy is thus a key process underpinning germination and seedling survival. Using live imaging, we investigated reactivation of mitochondrial bioenergetics and dynamics using Arabidopsis thaliana as a model. Bioenergetic reactivation, visualized by presence of a membrane potential, is immediate upon rehydration. However, reactivation of mitochondrial dynamics only occurs after transfer to germination conditions. Reactivation of mitochondrial bioenergetics is followed by dramatic reorganization of the chondriome (all mitochondrial in a cell, collectively) involving massive fusion and membrane biogenesis to form a perinuclear tubuloreticular structure enabling mixing of previously discrete mitochondrial DNA nucleoids. The end of germination coincides with fragmentation of the chondriome, doubling of mitochondrial number, and heterogeneous redistribution of nucleoids among the mitochondria, generating a population of mitochondria tailored to seedling growth. PMID:28062752

  1. Capillary pressure as a unique function of electric permittivity and water saturation

    NARCIS (Netherlands)

    Plug, W.J.; Slob, E.; Van Turnhout, J.; Bruining, J.

    2007-01-01

    The relation between capillary pressure (Pc) and interfacial area has been investigated by measuring Pc and the electric permittivity at 100 kHz simultaneously as function of the water saturation, (Sw). Drainage and imbibition experiments have been conducted for sand-distilled water-gas (CO2/N2)

  2. Mechanisms for Hysteresis in a Horizontal Unsaturated Fracture with Matric Imbibition

    Science.gov (United States)

    Fox, D. T.; Glass, R. J.

    2002-12-01

    Within porous media, macroscopic hysteretic pressure-saturation relations have long been thought to be the result of microscopic effects such as phase invasion within local `ink bottle' geometry, phase trapping or accessibility, and differences between solid-liquid-liquid contact angles for wetting and nonwetting invasion. Here we consider the mechanisms for hysteresis within a horizontal rough-walled fracture. An analogue horizontal rough-walled fracture (10 cm x 15 cm) was formed by placing a piece of transparent textured glass against a water saturated, flat porous plate. Water could enter and leave the fracture via the porous plate while air entered or left via the fracture edges. The evolution of wetted structure within the fracture was recorded with digital images taken through the transparent side as the tension in the porous plate was raised and lowered. Following a sequence of such invasion experiments, the porous plate was replaced with a piece of flat glass and the aperture field was measured using a light transmission technique. Analysis of digital images taken during displacement demonstrated that the macroscopic hysteresis in pressure-saturation curves resulted primarily from the underlying microscopic mechanisms of ink bottle and phase trapping accessibility. Additionally, we found the wetted structure within the fracture to become connected and form a satiated (0 tension) structure containing complex entrapped air structures (volumetric saturation ~0.5) thus greatly reducing permeability at 0 tension. The pressure at which this structure formed on wetting and fragmented on drainage also showed significant hysteresis.

  3. Droplet spreading and capillary imbibition in a porous medium: A coupled IB-VOF method based numerical study

    Science.gov (United States)

    Das, Saurish; Patel, H. V.; Milacic, E.; Deen, N. G.; Kuipers, J. A. M.

    2018-01-01

    We investigate the dynamics of a liquid droplet in contact with a surface of a porous structure by means of the pore-scale level, fully resolved numerical simulations. The geometrical details of the solid porous matrix are resolved by a sharp interface immersed boundary method on a Cartesian computational grid, whereas the motion of the gas-liquid interface is tracked by a mass conservative volume of fluid method. The numerical simulations are performed considering a model porous structure that is approximated by a 3D cubical scaffold with cylindrical struts. The effect of the porosity and the equilibrium contact angle (between the gas-liquid interface and the solid struts) on the spreading behavior, liquid imbibition, and apparent contact angle (between the gas-liquid interface and the porous base) are studied. We also perform several simulations for droplet spreading on a flat surface as a reference case. Gas-liquid systems of the Laplace number, La = 45 and La = 144 × 103 are considered neglecting the effect of gravity. We report the time exponent (n) and pre-factor (C) of the power law describing the evolution of the spreading diameter (S = Ctn) for different equilibrium contact angles and porosity. Our simulations reveal that the apparent or macroscopic contact angle varies linearly with the equilibrium contact angle and increases with porosity. Not necessarily for all the wetting porous structures, a continuous capillary drainage occurs, and we find that the rate of the capillary drainage very much depends on the fluid inertia. At La = 144 × 103, numerically we capture the capillary wave induced pinch-off and daughter droplet ejection. We observe that on the porous structure the pinch-off is weak compared to that on a flat plate.

  4. Hydraulic transport across hydrophilic and hydrophobic nanopores: Flow experiments with water and n -hexane

    Science.gov (United States)

    Gruener, Simon; Wallacher, Dirk; Greulich, Stefanie; Busch, Mark; Huber, Patrick

    2016-01-01

    We experimentally explore pressure-driven flow of water and n -hexane across nanoporous silica (Vycor glass monoliths with 7- or 10-nm pore diameters, respectively) as a function of temperature and surface functionalization (native and silanized glass surfaces). Hydraulic flow rates are measured by applying hydrostatic pressures via inert gases (argon and helium, pressurized up to 70 bar) on the upstream side in a capacitor-based membrane permeability setup. For the native, hydrophilic silica walls, the measured hydraulic permeabilities can be quantitatively accounted for by bulk fluidity provided we assume a sticking boundary layer, i.e., a negative velocity slip length of molecular dimensions. The thickness of this boundary layer is discussed with regard to previous capillarity-driven flow experiments (spontaneous imbibition) and with regard to velocity slippage at the pore walls resulting from dissolved gas. Water flow across the silanized, hydrophobic nanopores is blocked up to a hydrostatic pressure of at least 70 bar. The absence of a sticking boundary layer quantitatively accounts for an enhanced n -hexane permeability in the hydrophobic compared to the hydrophilic nanopores.

  5. Effect of cationic surfactants on organic liquid-water capillary pressure-saturation relationships

    Science.gov (United States)

    Demond, A. H.; Desai, F. N.; Hayes, K. F.

    1994-02-01

    Many solutes, either naturally occurring or introduced, are surface active and sorb preferentially at the interfaces of subsurface systems. In multiphase systems, the sorption of surfactants affects the capillary pressure-saturation relationships, fundamental constitutive relationships in the modeling of multiphase flow. In this study, the impact of surfactant sorption on capillary pressure relationships for organic liquid-waters systems was demonstrated by qualitatively correlating measurements of sorption and zeta potential, with interfacial tension and contact angle and, in turn, quantitatively relating these measurements to changes in capillary pressure-saturation relationships for o-xylene-water-quartz systems containing a cationic surfactant, cetyltrimethylammonium bromide (CTAB). The results show that the sorption of CTAB causes the naturally hydrophilic system to become hydrophobic, as evidenced by a change in the contact angle from about 10°-15° to 155° or 180°, depending on the pH. This change in hydrophilicity is reflected in the zeta potential of the system which goes from negative to positive as the aqueous phase CTAB concentration increases. The spontaneous imbibition capillary pressure-saturation relationship is more sensitive to the sorption of CTAB than the drainage relationship. To predict the observed changes in both capillary pressure-saturation relationships, a modified form of Leverett's function was used where roughness and curvature corrections were incorporated into the intrinsic contact angle to give an operational contact angle. A comparison of the measured and predicted capillary pressure-saturation relationships showed reasonable agreement.

  6. A study of water relations in neem (Azadirachta indica) seed that is characterised by complex storage behaviour

    NARCIS (Netherlands)

    Sacandé, M.; Buitink, J.; Hoekstra, F.A.

    2000-01-01

    Neem (Azadirachta indica) seed is reputed to have limited tolerance to desiccation, to be sensitive to chilling and imbibitional stress, and to display intermediate storage behaviour. To understand this behaviour the properties of water in seed tissues were studied. Water sorption isotherms showed

  7. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  8. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  9. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  10. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  11. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  12. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  13. Release of E.coli D21g with transients in water content

    Science.gov (United States)

    Transients in water content are well known to mobilize microorganisms that are retained in the vadose zone. However, there is no consensus on the relative importance of drainage and imbibition events on microorganism release. To overcome this limitation, we have systematically studied the release o...

  14. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  15. Contact Angles of Water-repellent Porous Media Inferred by Tensiometer- TDR Probe Measurement Under Controlled Wetting and Drying Cycles

    DEFF Research Database (Denmark)

    Subedi, Shaphal; Komatsu, Ken; Komatsu, Toshiko

    2013-01-01

    The time dependency of water repellency (WR) in hydrophobic porous media plays a crucial role for water infiltration processes after rainfall and for the long-term performance of capillary barrier systems. The contact angle (CA) of hydrophobic media normally decreases with continuous contact...... with water, eventually allowing water imbibition. However, the effect of the reduction in CA with soil-water contact time on the water retention function of hydrophobic media is not yet fully understood. In this study, water retention characteristics were measured using a hanging water column apparatus...... equipped with a mini-time domain reflectometry (TDR) coil probe under controlled wetting and drying in a water-repellent volcanic ash soil (VAS) and in sands coated with different hydrophobic agents. The contact angle (CA–SWRC) under imbibition was evaluated based on the inflection points on the water...

  16. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  17. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  18. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  19. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  20. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  1. Capillary pressure heterogeneity and hysteresis for the supercritical CO2/water system in a sandstone

    Science.gov (United States)

    Pini, Ronny; Benson, Sally M.

    2017-10-01

    We report results from an experimental investigation on the hysteretic behaviour of the capillary pressure curve for the supercritical CO2-water system in a Berea Sandstone core. Previous observations have highlighted the importance of subcore-scale capillary heterogeneity in developing local saturations during drainage; we show in this study that the same is true for the imbibition process. Spatially distributed drainage and imbibition scanning curves were obtained for mm-scale subsets of the rock sample non-invasively using X-ray CT imagery. Core- and subcore-scale measurements are well described using the Brooks-Corey formalism, which uses a linear trapping model to compute mobile saturations during imbibition. Capillary scaling yields two separate universal drainage and imbibition curves that are representative of the full subcore-scale data set. This enables accurate parameterisation of rock properties at the subcore-scale in terms of capillary scaling factors and permeability, which in turn serve as effective indicators of heterogeneity at the same scale even when hysteresis is a factor. As such, the proposed core-analysis workflow is quite general and provides the required information to populate numerical models that can be used to extend core-flooding experiments to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.

  2. Temperatura óptima de germinación y patrones de imbibición de las semillas de Albizia lebbeck, Gliricidia sepium y Bauhinia purpurea Optimum germination temperature and imbibition patterns of the seeds from Albizia lebbeck, Gliricidia sepium and Bauhinia purpurea

    Directory of Open Access Journals (Sweden)

    J Reino

    2008-09-01

    substratum (constant 25ºC and three alternate ones: 25/30ºC, 25/35ºC and 25/40ºC. Before seeding the seeds of A. lebbeck were scarified (water at 80ºC/2'. For the imbibition pattern the seeds were put on filter paper moist with purified water according to the optimum germination temperature, under white fluorescent light and at different imbibition times. In the fresh seeds of all the species the highest percentages of final germination were obtained at alternate temperature of 25/35ºC and in the aged ones at 25/30ºC. With regards to the imbibition pattern they all followed a three-phase pattern of water absorption. The fresh and aged seeds of G. sepium showed a very similar imbibition pattern, however the fresh seeds of the other species presented higher hydration rate than the aged ones and consequently they reached faster the start of phase III of the imbibition pattern (i.e. visible germination. The range of optimum temperature for the germination of aged seeds was concluded to be 25/30 ºC and for the fresh ones it was 25/35 ºC and both showed a three-phase pattern of water absorption when the seeding was carried out at optimum germination temperature.

  3. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  4. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  5. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  6. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  7. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  8. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  9. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  10. Variations of petrophysical properties and spectral induced polarization in response to drainage and imbibition: a study on a correlated random tube network

    Science.gov (United States)

    Maineult, Alexis; Jougnot, Damien; Revil, André

    2018-02-01

    We implement a procedure to simulate the drainage and imbibition in random, 2-D, square networks. We compute the resistivity index, the relative permeability and the characteristic lengths of a correlated network at various saturation states, under the assumption that the surface conductivity can be neglected. These parameters exhibit a hysteretic behaviour. Then, we calculate the spectral induced polarization (SIP) response of the medium, under the assumption that the electrical impedance of each tube follows a local Warburg conductivity model, with identical DC conductivity and chargeability for all the tubes. We evidence that the shape of the SIP spectra depends on the saturation state. The analysis of the evolution of the macroscopic Cole-Cole parameters of the spectra in function of the saturation also behaves hysteretically, except for the Cole-Cole exponent. We also observe a power-law relationship between the macroscopic DC conductivity and time constant and the relative permeability. We also show that the frequency peak of the phase spectra is directly related to the characteristic length and to the relative permeability, underlining the potential interest of SIP measurements for the estimation of the permeability of unsaturated media.

  11. Electrical current nanogeneration driven by spontaneous nanofluidic oscillations.

    Science.gov (United States)

    Gimenez, R; Mercuri, M; Berli, C L A; Bellino, M G

    2018-02-15

    Exploiting natural phenomena is a central route for providing electricity to sustainably drive wearable electronics. Here we report a nano-scale water-driven energy generator that produces tiny electrical currents from spontaneous wetting-drying oscillations in mesoporous thin films. The system was fabricated with a wormlike mesoporous silica film, which was packed in between Cu and silicon contacts. The nanogenerator runs autonomously when a water droplet is laid over the film close to the Cu electrode, as water infiltration into the film under the electrode produces a direct-current. Wetting-drying cycles, which are spontaneously triggered by water evaporation, are perfectly correlated to the generated electrical current. The autonomous water displacement through the film yields a sustained energy conversion until the droplet reservoir vanishes. This novel water-driven nanogenerator opens new alternatives for versatile, mobile and cost-effective self-powering of nanosystems and nanodevices.

  12. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  13. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  14. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  15. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  16. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  17. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  18. Spontaneous emulsification at surfactantless liquid/liquid interfaces

    Czech Academy of Sciences Publication Activity Database

    Silver, Barry Richard; Holub, Karel; Mareček, Vladimír

    2017-01-01

    Roč. 805, NOV 2017 (2017), s. 91-97 ISSN 1572-6657 R&D Projects: GA ČR(CZ) GA17-09980S Institutional support: RVO:61388955 Keywords : ities * Open circuit potential * Spontaneous emulsification * Water-in- oil Subject RIV: CG - Electrochemistry OBOR OECD: Physical chemistry Impact factor: 3.012, year: 2016

  19. Observation of spontaneous combustion of hydrogen and oxygen in microbubbles

    NARCIS (Netherlands)

    Postnikov, A.V.; Uvarov, I.V.; Prokaznikov, A.V.; Svetovoy, Vitaly

    2016-01-01

    Experimental evidence is presented that combustion can ignite at room temperature spontaneously inside microbubbles filled with mixture of hydrogen and oxygen. We perform water electrolysis in a closed microchamber by voltage pulses of alternating polarity at repetition frequencies 100 kHz to pump

  20. Spontaneous emulsification at surfactantless liquid/liquid interfaces

    Czech Academy of Sciences Publication Activity Database

    Silver, Barry Richard; Holub, Karel; Mareček, Vladimír

    2017-01-01

    Roč. 805, NOV 2017 (2017), s. 91-97 ISSN 1572-6657 R&D Projects: GA ČR(CZ) GA17-09980S Institutional support: RVO:61388955 Keywords : ities * Open circuit potential * Spontaneous emulsification * Water-in-oil Subject RIV: CG - Electrochemistry OBOR OECD: Physical chemistry Impact factor: 3.012, year: 2016

  1. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  2. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  3. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  4. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    imbibition, which has been applied in most of the previous studies. Two different flooding schemes (with and without aging) were used for flooding North Sea reservoir chalk samples. For comparison, two tests were also carried out with Stevns Klint core plugs. The flooding tests were carried out...... composition but also the formation water composition affected the oil recovery at high temperatures from the Stevns Klint chalk rock....

  5. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  6. Mobilização de reservas em sementes de Apuleia leiocarpa (Vogel J.F. Macbr. (garapa durante a embebição Seed reserve mobilization of Apuleia leiocarpa (Vogel J.F. Macbr. (garapa during imbibition

    Directory of Open Access Journals (Sweden)

    Claudia Aparecida Pontes

    2002-10-01

    Full Text Available Quantificou-se a mobilização de reservas no eixo embrionário, nos cotilédones e no tegumento de sementes de Apuleia leiocarpa (garapa, durante a germinação. Os resultados mostram que houve aumento significativo das reservas de amido, ácido esteárico e proteína nos cotilédones durante o processo de embebição. Por outro lado, no embrião houve aumento significativo somente nos teores de manose, enquanto as reservas dos ácidos graxos mirístico, palmítico, esteárico, oléico e linoléico decresceram significativamente. Os teores de manose e galactose aumentaram significativamente no tegumento. Com exceção do ácido láurico, todos os demais não foram detectados após 48 horas de embebição.The mobilization of reserves was quantified in the embryonic axis, cotyledons and tegument of seeds of Apuleia leiocarpa (garapa during imbibition. The results show that there was a significant increase in the contents of starch, estearic acid and protein in the cotyledons during the imbibition process. On the other hand, there was only a significant manose content increase in the embryo while the reserves of fatty acids mirístic, palmitic, estearic, oleic and linoleic decreased significantly. Mannose and galactose contents increased significantly in the tegument. Except for the lauric acid, all others were not detected after 48 hours of imbibition.

  7. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  8. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  9. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  10. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  11. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  12. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  13. Quantitative high-resolution observations of soil water dynamics in a complicated architecture with time-lapse Ground-Penetrating Radar

    OpenAIRE

    P. Klenk; S. Jaumann; K. Roth

    2014-01-01

    High-resolution time-lapse Ground-Penetrating Radar (GPR) observations of advancing and retreating water tables can yield a wealth of information about near-surface water content dynamics. In this study, we present and analyze a series of imbibition, drainage and infiltration experiments which have been carried out at our artificial ASSESS test site and observed with surface based GPR. The test site features a complicated but known subsurface architecture co...

  14. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  15. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  16. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  17. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  18. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  20. Spontaneous baryogenesis in warm inflation

    OpenAIRE

    Brandenberger, Robert H.; Yamaguchi, Masahide

    2003-01-01

    We discuss spontaneous baryogenesis in the warm inflation scenario. In contrast with standard inflation models, radiation always exists in the warm inflation scenario, and the inflaton must be directly coupled to it. Also, the transition to the post-inflationary radiation dominated phase is smooth and the entropy is not significantly increased at the end of the period of inflation. In addition, after the period of warm inflation ends, the inflaton does not oscillate coherently but slowly roll...

  1. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  2. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  3. General features of spontaneous baryogenesis

    Science.gov (United States)

    Arbuzova, Elena

    2017-04-01

    The classical version of spontaneous baryogenesis is studied in details. It is shown that the relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks). The kinetic equation, used for the calculations of the cosmological baryon asymmetry, is generalized to the case of non-stationary background. The effects of the finite interval of the integration over time are also included into consideration.

  4. Spontaneous osteonecrosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Kattapuram, Taj M. [Department of Radiology, Massachusetts General Hospital (United States); Kattapuram, Susan V. [Department of Radiology, Massachusetts General Hospital (United States)], E-mail: skattapuram@partners.org

    2008-07-15

    Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be ' subchondral insufficiency fracture of the knee' or 'focal subchondral osteonecrosis'.

  5. Water

    Science.gov (United States)

    ... environment and your health: Green living Sun Water Health effects of water pollution How to protect yourself from water pollution Air ... can hurt your health. Learn more about the health effects of polluted water. You can also learn more ... Source: U.S. Environmental Protection Agency Here are ...

  6. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  7. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  8. Spontaneity of communication in individuals with autism.

    Science.gov (United States)

    Chiang, Hsu-Min; Carter, Mark

    2008-04-01

    This article provides an examination of issues related to spontaneity of communication in children with autism. Deficits relating to spontaneity or initiation are frequently reported in individuals with autism, particularly in relation to communication and social behavior. Nevertheless, spontaneity is not necessarily clearly conceptualized or measured. Several approaches to conceptualization of communicative spontaneity are examined with a particular focus on the continuum model and how it might be practically applied. A range of possible explanations for deficits in spontaneity of communication in children with autism is subsequently explored, including external factors (highly structured teaching programs, failure to systematically instruct for spontaneity) and intrinsic characteristics (intellectual disability, stimulus overselectivity, weak central coherence). Possible implications for future research are presented.

  9. Spontaneous cryptococcal peritonitis in cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Sungkanuparph S

    2002-07-01

    Full Text Available Spontaneous bacterial peritonitis is a common complication in patients with cirrhosis and ascites. However, spontaneous peritonitis caused by Cryptococcus neoformans is uncommon. Delayed diagnosis of cryptococcal peritonitis often results in death. We describe three cases of spontaneous cryptococcal peritonitis in patients with decompensated cirrhosis. One case had associated symptomatic human immunodeficiency virus infection. Clinical awareness of this entity may lead to the early diagnosis and proper treatment.

  10. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  11. Spontaneous renal hematoma - a case report

    International Nuclear Information System (INIS)

    Obrzut, M.; Obrzut, M.; Homa, J.; Obrzut, B.

    2006-01-01

    Spontaneous pararenal hematoma is a rare pathology most frequently coexisting with renal tumours, vascular anomalies and inflammatory processes. In some cases one cannot establish its etiology. The paper describes a case of a 58-year-old man with a spontaneous pararenal hematoma and presents a diagnostic algorithm. Ultrasonography and CT play an important role in diagnostics of spontaneous pararenal haemorrhages. These methods enable a precise evaluation of size and location of hematoma and its evolution. (author)

  12. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  13. Water

    International Nuclear Information System (INIS)

    Chovanec, A.; Grath, J.; Kralik, M.; Vogel, W.

    2002-01-01

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  14. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available to explore desalination for future capacity. Water is essential to life: the human body is about 75 percent water, with up to 85 percent of brain cells liquid. Around 71 percent of the planet is covered in water, but 97,5 percent of it is salt water... risen to 90 percent, leaving only 10 percent for animals and plants. Yet 40 percent of the water used globally is for sanitation and other uses in buildings. The operation of buildings places a strain on raw water reserves, while wastewater and sewage...

  15. Electrical conductivity and mineral composition of the imbibition solution of bean seeds during storage Condutividade elétrica e composição mineral da solução de embebição de sementes de feijão durante o armazenamento

    Directory of Open Access Journals (Sweden)

    Claudia Denise da Silva

    2012-04-01

    Full Text Available The electrical conductivity test has been used to evaluate seed vigour in many species, especially legumes, such as peas, beans and soybeans. The objective of this research was to evaluate the effect of temperature and storage period on the results of the electrical conductivity test and the mineral composition of the imbibition solution of bean seeds (Phaseolus vulgaris L.. Three seed lots of the cultivar IAPAR - 81 and cultivar IPR - TIZIU were stored at 10, 25 and 25-10º C (six months at 10º C and six months at 25º C The following evaluations were made every three months for a year: seed water content, germination and vigour (accelerated ageing and electrical conductivity and the potassium, calcium and magnesium contents of the imbibition solution. The cultivars showed similar behavior in storage. The reduction in the vigour of bean seeds stored at 10º C was verified by accelerated ageing and electrical conductivity tests. The bean seed storage at low temperature (10º C does not influence the results of the evaluation of seed vigour by electrical conductivity test and the quantification of calcium, magnesium and potassium ions. The evaluation of vigour by the electrical conductivity test is not recommended for bean seed stored by long periods (above 9 months.O teste de condutividade elétrica tem sido usado para avaliar o vigor de sementes de muitas espécies, especialmente de fabáceas, como ervilha, feijão e soja. Assim, nesta pesquisa, objetivou-se avaliar o efeito da temperatura e do período de armazenamento sobre os resultados do teste de condutividade elétrica e da composição mineral da solução de embebição de sementes de feijão (Phaseolus vulgaris L.. Foram utilizados três lotes do cultivar IAPAR - 81 (grupo "Carioca" e três do cultivar IPR - TIZIU (grupo "Preto" armazenados a 10, 25 e 25-10º C (seis meses a 10º C e seis meses a 25º C. Ao longo de 12 meses de armazenamento, a cada três meses foram determinados

  16. Water

    Science.gov (United States)

    ... Marion County, Indiana Salt Lake County, Utah Seattle-King County, Washington Tools and Training CLPPP CAP Healthy ... wish to use tap water for drinking or cooking, especially when the water has been off and ...

  17. Biomarkers of spontaneous preterm birth

    DEFF Research Database (Denmark)

    Polettini, Jossimara; Cobo, Teresa; Kacerovsky, Marian

    2017-01-01

    predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis. Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal......Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable......) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods. By this systematic review, we conclude that multiplex assays...

  18. Spontaneous Strategies in Innovation Networks

    DEFF Research Database (Denmark)

    Plesner, Ursula; Husted, Emil Krastrup

    and a site ontology, we show how physical sites and objects become constitutive of the inside of virtual worlds through innovation processes. This argument is in line with ANT’s perspective on strategy, where sites and objects are considered a strategically relevant resource in the innovation process...... of materiality in relation to the organization and structuring of virtual worlds. We examine various innovation processes in five Danish entrepreneurial companies where actors continuously struggle to stabilize virtual worlds as platforms for professional communication. With inspiration from actor-network theory....... Empirically, the analysis is founded on descriptive accounts from the five entrepreneurs. By highlighting the spontaneous strategies described by actors, we show how sites and objects are actively used as an element in their strategy, and also how the sites and objects end up facilitating new ways of thinking...

  19. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  20. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. The microfluidic Kelvin water dropper

    NARCIS (Netherlands)

    Gomez Marin, Alvaro; van Hoeve, W.; García-Sánchez, Pablo; Shui, Lingling; Xie, Yanbo; Fontelos, Marco A.; Eijkel, Jan C.T.; van den Berg, Albert; Lohse, Detlef

    2013-01-01

    The so-called "Kelvin water dropper" is a simple experiment demonstrating the spontaneous appearance of induced free charge in droplets emitted through a tube. As Lord Kelvin explained, water droplets spontaneously acquire a net charge during detachment from a faucet due to the presence of

  2. Stabiliteit spontane taal bij chronische milde afasie

    NARCIS (Netherlands)

    Wolthuis, Nienke; Mendez Orellana, Carolina; Nouwens, Femke; Jonkers, Roel; Visch-Brink, Evy; Bastiaanse, Roelien

    2014-01-01

    In aphasia, an analysis of spontaneous speech provides opportunities to establish the linguistic and communicative abilities, to create suitable therapy plans and to measure language progress. The current study investigated the stability of spontaneous speech within an interview of ten mild aphasic

  3. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  4. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  5. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  6. Spontaneity and Equilibrium II: Multireaction Systems

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  7. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  8. The (perceived) meaning of spontaneous thoughts.

    Science.gov (United States)

    Morewedge, Carey K; Giblin, Colleen E; Norton, Michael I

    2014-08-01

    Spontaneous thoughts, the output of a broad category of uncontrolled and inaccessible higher order mental processes, arise frequently in everyday life. The seeming randomness by which spontaneous thoughts arise might give people good reason to dismiss them as meaningless. We suggest that it is precisely the lack of control over and access to the processes by which they arise that leads people to perceive spontaneous thoughts as revealing meaningful self-insight. Consequently, spontaneous thoughts potently influence judgment. A series of experiments provides evidence supporting two hypotheses. First, we hypothesize that the more a thought is perceived to be spontaneous, the more it is perceived to provide meaningful self-insight. Participants perceived more spontaneous kinds of thought (e.g., intuition) to reveal greater self-insight than did more controlled kinds of thought in Study 1 (e.g., deliberation). In Studies 2 and 3, participants perceived thoughts with the same content and target to reveal greater self-insight when spontaneously rather than deliberately generated (i.e., childhood memories and impressions formed). Second, we hypothesize that the greater self-insight attributed to thoughts that are (perceived to be) spontaneous leads those thoughts to more potently influence judgment. Participants felt more sexually attracted to an attractive person whom they thought of spontaneously than deliberately in Study 4, and reported their commitment to a current romantic relationship would be more affected by the spontaneous rather than deliberate recollection of a good or bad experience with their romantic partner in Study 5. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  9. Spontaneous Assembly of Exopolymers from Phytoplankton

    Directory of Open Access Journals (Sweden)

    Yong-Xue Ding

    2009-01-01

    Full Text Available Phytoplankton exopolymeric substances (EPS contribute significantly to the dissolved organic car bon (DOC pool in the ocean, playing crucial roles in the surface ocean car bon cycle. Recent studies have demonstrated that ~10% of marine DOC can self-assemble as microgels through electro static Ca bonds providing hotspots of enriched microbial substrate. How ever, the question whether EPS can self-assemble and the formation mechanisms for EPS microgels have not been examined. Here were port that EPS from three representative phytoplankton species, Synechococcus, Emiliania huxleyi, and Skeletonema costatum can spontaneously self assemble in artificial sea water (ASW, forming microscopic gels of ~ 3 - 4 __m in diameter. Different from the marine DOC polymers assembly, these EPS samples can self-assemble in Ca2+-free ASW. Further experiments from fluorescence enhancement and chemical composition analysis confirmed the existence of fair amounts of hydrophobic domains in these EPS samples. These results suggest that hydrophobic interactions play a key role in the assembly of EPS from these three species of marine phytoplankton.

  10. Structural study of the continuous medium of spontaneous ternary emulsions

    International Nuclear Information System (INIS)

    Desforge, Christine

    1993-01-01

    This research thesis addresses the study of the structure of a continuous medium of spontaneous ternary emulsions of oil-in-water type, composed of water and octane, and stabilised by means of a cationic surfactant (DDAB, didodecyldimethyl ammonium bromide). It shows that the kinetic stability is due to electrostatic repulsions between octane drops, and that these repulsions are due to the presence of positive charges on the DDAB mono-layer located at the interface between water and oil. Various aspects are highlighted by neutron and X ray scattering. In this study, the DDAB is replaced by a non-ionic surfactant. Its use results in very steady oil/water emulsions [fr

  11. Spontaneous Metacognition in Rhesus Monkeys.

    Science.gov (United States)

    Rosati, Alexandra G; Santos, Laurie R

    2016-09-01

    Metacognition is the ability to think about thinking. Although monitoring and controlling one's knowledge is a key feature of human cognition, its evolutionary origins are debated. In the current study, we examined whether rhesus monkeys (Macaca mulatta; N = 120) could make metacognitive inferences in a one-shot decision. Each monkey experienced one of four conditions, observing a human appearing to hide a food reward in an apparatus consisting of either one or two tubes. The monkeys tended to search the correct location when they observed this baiting event, but engaged in information seeking-by peering into a center location where they could check both potential hiding spots-if their view had been occluded and information seeking was possible. The monkeys only occasionally approached the center when information seeking was not possible. These results show that monkeys spontaneously use information about their own knowledge states to solve naturalistic foraging problems, and thus provide the first evidence that nonhumans exhibit information-seeking responses in situations with which they have no prior experience. © The Author(s) 2016.

  12. Spontaneous flocking in human groups.

    Science.gov (United States)

    Belz, Michael; Pyritz, Lennart W; Boos, Margarete

    2013-01-01

    Flocking behaviour, as a type of self-organised collective behaviour, is described as the spatial formation of groups without global control and explicit inter-individual recruitment signals. It can be observed in many animals, such as bird flocks, shoals or herds of ungulates. Spatial attraction between humans as the central component of flocking behaviour has been simulated in a number of seminal models but it has not been detected experimentally in human groups so far. The two other sub-processes of this self-organised collective movement - collision avoidance and alignment - are excluded or held constant respectively in this study. We created a computer-based, multi-agent game where human players, represented as black dots, moved on a virtual playground. The participants were deprived of social cues about each other and could neither communicate verbally nor nonverbally. They played two games: (1) Single Game, where other players were invisible, and (2) Joint Game, where each player could see players' positions in a local radius around himself/herself. We found that individuals approached their neighbours spontaneously if their positions were visible, leading to less spatial dispersion of the whole group compared to moving alone. We conclude that human groups show the basic component of flocking behaviour without being explicitly instructed or rewarded to do so. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Simultaneous bilateral primary spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Arife Zeybek

    2014-04-01

    Full Text Available Simultaneous bilateral primary pneumothorax is a very rare (1.6 / 100,000 and life-threatening condition. Clinical presentation may vary from mild dyspnea to tension pneumothorax. It may be milder particularly in younger patients, but more severe in patients with advanced age, and tube thoracostomy is a life preserver in the latter group. Since mortality and recurrence rates following tube thoracostomy are high, endoscopic approaches to bilateral hemithorax have been reported in literature. Apical wedge resection and pleural procedures are recommended in video thoracoscopy or mini thoracotomy even if no bulla and/or bleb are detected. Bilateral surgical interventions and additional pleural procedures are associated with increased rate of post-operative complications and longer postoperative hospital-stays. As a first-line approach, the surgical method toward any side of lung with air leakage following a previous tube thoracostomy is considered less invasive, especially in younger patients. Here, we present a case of simultaneous bilateral primary spontaneous pneumothorax (SBPSP in a 21-year old male with no history of smoking and chronic pulmonary disease. A unilateral surgical intervention was performed, and no recurrence was observed during 5-year follow up.

  14. Bilateral spontaneous hemotympanum: Case report

    Directory of Open Access Journals (Sweden)

    Economou Nicolas C

    2006-10-01

    Full Text Available Abstract Background The most common causes of hemotympanum are therapeutic nasal packing, epistaxis, blood disorders and blunt trauma to the head. Hemotympanum is characterized as idiopathic, when it is detected in the presence of chronic otitis media. A rare case of spontaneous bilateral hemotympanum in a patient treated with anticoagulants is presented herein. Case presentation A 72-year-old male presented with acute deterioration of hearing. In the patient's medical history aortic valve replacement 1 year before presentation was reported. Since then he had been administered regularly coumarinic anticoagulants, with INR levels maintained between 3.4 and 4.0. Otoscopy revealed the presence of bilateral hemotympanum. The audiogram showed symmetrical moderately severe mixed hearing loss bilaterally, with the conductive component predominating. Tympanograms were flat bilaterally with absent acoustic reflexes. A computerized tomography scan showed the presence of fluid in the mastoid and middle ear bilaterally. Treatment was conservative and consisted of a 10-day course of antibiotics, anticongestants and temporary interruption of the anticoagulant therapy. After 3 weeks, normal tympanic membranes were found and hearing had returned to previous levels. Conclusion Anticoagulant intake should be included in the differential diagnosis of hemotympanum, because its detection and appropriate treatment may lead to resolution of the disorder.

  15. Water

    OpenAIRE

    Hertie School of Governance

    2010-01-01

    All human life depends on water and air. The sustainable management of both is a major challenge for today's public policy makers. This issue of Schlossplatz³ taps the streams and flows of the current debate on the right water governance.

  16. ISOLATION AND IDENTIFICATION OF MICROORGANISMS DURING SPONTANEOUS FERMENTATION OF MAIZE [Isolasi dan Identifikasi Mikroorganisme pada Fermentasi Spontan Jagung

    Directory of Open Access Journals (Sweden)

    Rahmawati1,2

    2013-06-01

    Full Text Available Maize was traditionally the second most common staple food in Indonesia. Conversion to maize flour has been accomplished to improve its convenience. Traditionally, maize flour is produced by soaking the kernels in water followed by grinding. It was reported that final physicochemical characteristics of the maize flour were influenced by spontaneous fermentation which occurred during soaking. This research aimed to isolate and identify important microorganisms that grew during fermentation thus a standardized starter culture can be developed for a more controlled fermentation process. Soaking of maize grits was conducted in sterile water (grits:water=1:2, w/v in a closed container at room temperature (±28ºC for 72 hours. After 0, 4, 12, 24, 36, 48, 72 hours, water and maize grits were sampled and tested for the presence of mold, yeast, and lactic acid bacteria (LAB. Isolates obtained from the spontaneous fermentation were reinoculated into the appropriate media containing starch to observe their amylolytic activity. Individual isolate was then identified; mold by slide culture method, while yeast and LAB by biochemical rapid kits, i.e. API 20C AUX and API CH50, respectively. The number of each microorganism was plotted against time to obtain the growth curve of the microorganisms during spontaneous fermentation. The microorganisms were identified as Penicillium chrysogenum, P. citrinum, A. flavus, A. niger, Rhizopus stolonifer, R.oryzae, Fusarium oxysporum, Acremonium strictum, Candida famata, Kodamaea ohmeri, Candida krusei/incospicua, Lactobacillus plantarum 1a, Pediococcus pentosaceus, L. brevis 1, L. plantarum 1b, and L. paracasei ssp paracasei 3. Four molds and one yeast were amylolytic while none of the LAB was capable of starch hydrolysis. The growth curve suggested that the amylolitic mold and yeast grew to hydrolyze starch during the course of fermentation, while the LABs benefited from the hydrolyzed products and dominated the later

  17. Clock frequency estimation under spontaneous emission

    Science.gov (United States)

    Qin, Xi-Zhou; Huang, Jia-Hao; Zhong, Hong-Hua; Lee, Chaohong

    2018-02-01

    We investigate the quantum dynamics of a driven two-level system under spontaneous emission and its application in clock frequency estimation. By using the Lindblad equation to describe the system, we analytically obtain its exact solutions, which show three different regimes: Rabi oscillation, damped oscillation, and overdamped decay. From the analytical solutions, we explore how the spontaneous emission affects the clock frequency estimation. We find that under a moderate spontaneous emission rate, the transition frequency can still be inferred from the Rabi oscillation. Our results enable potential practical applications in frequency measurement and quantum control under decoherence.

  18. Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dalip Gupta

    2013-11-01

    Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

  19. Spontaneous regression of an invasive thymoma.

    Science.gov (United States)

    Yutaka, Yojiro; Omasa, Mitsugu; Shikuma, Kei; Okuda, Masato; Taki, Toshihiko

    2009-05-01

    Although there are many reports of spontaneous regression of noninvasive thymoma, there are no reports of spontaneous regression of an invasive thymoma. Moreover, the mechanism of the spontaneous regression is still unknown. The present case concerns a 47-year-old man who presented with chest pain. Computed tomography (CT) showed a large anterior mediastinal mass with left pleural effusion that occluded the innominate vein. The tissue obtained by video-assisted thoracic surgery suggested a diagnosis of invasive thymic carcinoma. One month later CT showed prominent regression of the tumor, and the tumor was completely resected. On pathology, the diagnosis was thymoma type B3.

  20. Spontaneous Dissection of the Superior Mesenteric Artery

    International Nuclear Information System (INIS)

    Sheldon, Patrick J.; Esther, James B.; Sheldon, Elana L.; Sparks, Steven R.; Brophy, David P.; Oglevie, Steven B.

    2001-01-01

    Spontaneous dissection of the superior mesenteric artery (SMA) is a rare occurrence, especially when not associated with aortic dissection. Currently, only 28 cases appear to have been reported. Due to the scarcity of cases in the literature, the natural history of isolated, spontaneous SMA dissection is unclear. CT has been reported to be useful for the initial diagnosis of SMA dissection [2-5]. We present two recent cases of spontaneous SMA dissection in which enhanced spiral CT was instrumental in following the disease process and guiding clinical decision making

  1. Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

    Science.gov (United States)

    Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

    2017-10-01

    We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

  2. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  3. Right Diaphragm Spontaneous Rupture: A Surgical Approach

    Directory of Open Access Journals (Sweden)

    Duilio Divisi

    2011-01-01

    Full Text Available We present a case of spontaneous rupture of the diaphragm, characterized by nonspecific symptoms. The rapid diagnosis and appropriate surgical approach led to a positive resolution of the pathology.

  4. Spontaneous cecal perforation secondary to acute fulminant ...

    African Journals Online (AJOL)

    Spontaneous cecal perforation secondary to acute fulminant gastroenteritis: report of a rare case. Duvuru Ram, Vilvapathy S. Karthikeyan, Sarath C. Sistla, Sheik M. Ali, Parnandi Sridhar, Nagarajan Rajkumar ...

  5. Spontaneous Trait Inferences on Social Media.

    Science.gov (United States)

    Levordashka, Ana; Utz, Sonja

    2017-01-01

    The present research investigates whether spontaneous trait inferences occur under conditions characteristic of social media and networking sites: nonextreme, ostensibly self-generated content, simultaneous presentation of multiple cues, and self-paced browsing. We used an established measure of trait inferences (false recognition paradigm) and a direct assessment of impressions. Without being asked to do so, participants spontaneously formed impressions of people whose status updates they saw. Our results suggest that trait inferences occurred from nonextreme self-generated content, which is commonly found in social media updates (Experiment 1) and when nine status updates from different people were presented in parallel (Experiment 2). Although inferences did occur during free browsing, the results suggest that participants did not necessarily associate the traits with the corresponding status update authors (Experiment 3). Overall, the findings suggest that spontaneous trait inferences occur on social media. We discuss implications for online communication and research on spontaneous trait inferences.

  6. Spontane abdominale arteriovenøse fistler

    DEFF Research Database (Denmark)

    Flarup, S; Lindholt, Jes Sanddal

    1997-01-01

    Spontaneous arteriovenous fistulas between major abdominal vessels (AAVF) complicates about 1% of abdominal aortic aneurysms. AAVF produces severe circulatory disturbances with high operative mortality. Preoperative diagnosis is important but difficult due to the varied nature of presentation. Fo...

  7. Depressive disorder and grief following spontaneous abortion.

    Science.gov (United States)

    Kulathilaka, Susil; Hanwella, Raveen; de Silva, Varuni A

    2016-04-12

    Abortion is associated with moderate to high risk of psychological problems such as depression, use of alcohol or marijuana, anxiety, depression and suicidal behaviours. The increased risk of depression after spontaneous abortion in Asian populations has not been clearly established. Only a few studies have explored the relationship between grief and depression after abortion. A study was conducted to assess the prevalence and risk factors of depressive disorder and complicated grief among women 6-10 weeks after spontaneous abortion and compare the risk of depression with pregnant women attending an antenatal clinic. Spontaneous abortion group consisted of women diagnosed with spontaneous abortion by a Consultant Obstetrician. Women with confirmed or suspected induced abortion were excluded. The comparison group consisted of randomly selected pregnant, females attending the antenatal clinics of the two hospitals. Diagnosis of depressive disorder was made according to ICD-10 clinical criteria based on a structured clinical interview. This assessment was conducted in both groups. The severity of depressive symptoms were assessed using the Patients Health Questionnaire (PHQ-9). Grief was assessed using the Perinatal Grief Scale which was administered to the women who had experienced spontaneous abortion. The sample consisted of 137 women in each group. The spontaneous abortion group (mean age 30.39 years (SD = 6.38) were significantly older than the comparison group (mean age 28.79 years (SD = 6.26)). There were more females with ≥10 years of education in the spontaneous abortion group (n = 54; SD = 39.4) compared to the comparison group (n = 37; SD = 27.0). The prevalence of depression in the spontaneous abortion group was 18.6 % (95 CI, 11.51-25.77). The prevalence of depression in the comparison group was 9.5 % (95 CI, 4.52-14.46). Of the 64 women fulfilling criteria for grief, 17 (26.6 %) also fulfilled criteria for a depressive episode. The relative risk of

  8. Postmenopausal spontaneous uterine perforation: Case report

    Science.gov (United States)

    İşlek Seçen, Elçin; Ağış, Hilal; Altunkaya, Canan; Avşar, Ayşe Filiz

    2015-01-01

    Spontaneous uterine rupture and generalized peritonitis caused by pyometra occurs rarely with high morbidity and mortality. A correct and definite diagnosis can be made with laparotomy or laparoscopy. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and gynecologic symptoms are less frequent, which makes preoperative diagnosis difficult. We report a case of a patient aged 82 years who underwent surgery for spontaneous uterine rupture and generalized peritonitis as a result of pyometra. PMID:28913055

  9. Endometriosis-related spontaneous diaphragmatic rupture.

    Science.gov (United States)

    Triponez, Frédéric; Alifano, Marco; Bobbio, Antonio; Regnard, Jean-François

    2010-10-01

    Non-traumatic, spontaneous diaphragmatic rupture is a rare event whose pathophysiology is not known. We report the case of endometriosis-related spontaneous rupture of the right diaphragm with intrathoracic herniation of the liver, gallbladder and colon. We hypothesize that the invasiveness of endometriotic tissue caused diaphragm fragility, which finally lead to its complete rupture without traumatic event. The treatment consisted of a classical management of diaphragmatic rupture, with excision of the endometriotic nodule followed by medical ovarian suppression for six months.

  10. Spontaneous regression of metastatic Merkel cell carcinoma.

    LENUS (Irish Health Repository)

    Hassan, S J

    2010-01-01

    Merkel cell carcinoma is a rare aggressive neuroendocrine carcinoma of the skin predominantly affecting elderly Caucasians. It has a high rate of local recurrence and regional lymph node metastases. It is associated with a poor prognosis. Complete spontaneous regression of Merkel cell carcinoma has been reported but is a poorly understood phenomenon. Here we present a case of complete spontaneous regression of metastatic Merkel cell carcinoma demonstrating a markedly different pattern of events from those previously published.

  11. Spontaneous intracranial epidural hematoma during rivaroxaban treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jeronimo Buzetti; Jung, Gustavo Simiano; Silva Junior, Luis Fernando; Ramina, Ricardo, E-mail: leonardoruschel@yahoo.com.br [Instituto de Neurologia de Curitiba (INC), Curitiba, PR (Brazil)

    2016-11-15

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xarelto®. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban. (author)

  12. Spontaneous intracranial epidural hematoma during rivaroxaban treatment.

    Science.gov (United States)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jerônimo Buzetti; Jung, Gustavo Simiano; Silva, Luis Fernando; Ramina, Ricardo

    2016-11-01

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xareltor. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban.

  13. Some physicochemical remarks on spontaneous emulsification of vitreal tamponades.

    Science.gov (United States)

    Costagliola, Ciro; Semeraro, Francesco; dell'Omo, Roberto; Zeppa, Lucio; Bufalo, Gennaro; Cardone, Michele; Romano, Mario; Ambrosone, Luigi

    2014-01-01

    The importance of gravitational instability in determining the emulsification of vitreal tamponades is discussed. Theoretical results and numerical simulations indicate that the spontaneous formation of water-silicon oil is a rare event and that the very low concentration of surface active agents cannot justify the systematic formation of emulsions. The gravitational instabilities seem to play the main role. Our theoretical results seem in agreement with the experimental evidences; furthermore they indicate a future research line for the improvement of endotamponades. Indeed, the use of biodegradable antifoam may avoid the formation of bubbles and delay the formation of emulsions.

  14. Some Physicochemical Remarks on Spontaneous Emulsification of Vitreal Tamponades

    Directory of Open Access Journals (Sweden)

    Ciro Costagliola

    2014-01-01

    Full Text Available The importance of gravitational instability in determining the emulsification of vitreal tamponades is discussed. Theoretical results and numerical simulations indicate that the spontaneous formation of water-silicon oil is a rare event and that the very low concentration of surface active agents cannot justify the systematic formation of emulsions. The gravitational instabilities seem to play the main role. Our theoretical results seem in agreement with the experimental evidences; furthermore they indicate a future research line for the improvement of endotamponades. Indeed, the use of biodegradable antifoam may avoid the formation of bubbles and delay the formation of emulsions.

  15. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  16. The floating water bridge

    International Nuclear Information System (INIS)

    Fuchs, Elmar C; Woisetschlaeger, Jakob; Gatterer, Karl; Maier, Eugen; Pecnik, Rene; Holler, Gert; Eisenkoelbl, Helmut

    2007-01-01

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  17. Unraveling Key Metabolomic Alterations in Wheat Embryos Derived from Freshly Harvested and Water-Imbibed Seeds of Two Wheat Cultivars with Contrasting Dormancy Status

    Directory of Open Access Journals (Sweden)

    Aayudh Das

    2017-07-01

    Full Text Available Untimely rains in wheat fields during harvest season can cause pre-harvest sprouting (PHS, which deteriorates the yield and quality of wheat crop. Metabolic homeostasis of the embryo plays a role in seed dormancy, determining the status of the maturing grains either as dormant (PHS-tolerant or non-dormant (PHS-susceptible. Very little is known for direct measurements of global metabolites in embryonic tissues of dormant and non-dormant wheat seeds. In this study, physiologically matured and freshly harvested wheat seeds of PHS-tolerant (cv. Sukang, dormant and PHS-susceptible (cv. Baegjoong, non-dormant cultivars were water-imbibed, and the isolated embryos were subjected to high-throughput, global non-targeted metabolomic profiling. A careful comparison of identified metabolites between Sukang and Baegjoong embryos at 0 and 48 h after imbibition revealed that several key metabolic pathways [such as: lipids, fatty acids, oxalate, hormones, the raffinose family of oligosaccharides (RFOs, and amino acids] and phytochemicals were differentially regulated between dormant and non-dormant varieties. Most of the membrane lipids were highly reduced in Baegjoong compared to Sukang, which indicates that the cell membrane instability in response to imbibition could also be a key factor in non-dormant wheat varieties for their untimely germination. This study revealed that several key marker metabolites (e.g., RFOs: glucose, fructose, maltose, and verbascose, were highly expressed in Baegjoong after imbibition. Furthermore, the data showed that the key secondary metabolites and phytochemicals (vitexin, chrysoeriol, ferulate, salidroside and gentisic acid, with known antioxidant properties, were comparatively low at basal levels in PHS-susceptible, non-dormant cultivar, Baegjoong. In conclusion, the results of this investigation revealed that after imbibition the metabolic homeostasis of dormant wheat is significantly less affected compared to non

  18. Spontaneous direct and reverse osmosis

    International Nuclear Information System (INIS)

    Valitov, N.Kh.

    1996-01-01

    It has been ascertained experimentally that in the course of separation of CsCl, KCl, NaCl aqueous solutions by semi-permeable membrane from distilled water the direct and then reverse osmosis are observed. The same sequence is observed in case of separation of CsCl aqueous solutions from NaCl of different concentrations. The reason for the direct and reverse osmosis has been explained. 5 refs.; 3 figs. 1 tab

  19. Spontaneous body movements in spatial cognition

    Directory of Open Access Journals (Sweden)

    Sergiu eTcaci Popescu

    2012-05-01

    Full Text Available People often perform spontaneous body movements during spatial tasks such as giving complex directions or orienting themselves on maps. How are these spontaneous gestures related to spatial problem-solving? We measured spontaneous movements during a perspective-taking task inspired by map reading. Analyzing the motion data to isolate rotation and translation components of motion in specific geometric relation to the task, we found out that most participants executed spontaneous miniature rotations of the head that were significantly related to the main task parameter. These head rotations were as if participants were trying to align themselves with the orientation on the map either in the image plane or on the ground plane, but with tiny amplitudes, typically below 1% of the actual movements. Our results are consistent with a model of sensorimotor prediction driving spatial reasoning. The efference copy of planned movements triggers this prediction mechanism. The movements themselves may then be mostly inhibited; the small spontaneous gestures that we measure are the visible traces of these planned but inhibited actions.

  20. Bilateral spontaneous rupture of 'hale' kidneys

    International Nuclear Information System (INIS)

    Naumov, N.; Zozikov, B.; Otzetov, A.; Kamenova, M.; Martinova, F.; Kalyonski, R.

    2002-01-01

    A rare case of spontaneous bilateral rupture of the kidneys, occurring consecutively over a one-year period in a young male patient with 'hale' kidneys until then, is described. The patient's past history and thorough examination performed do not justify to assign the case under the heading of some of the etiological factors as the underlying cause of spontaneous kidney rupture. The literature survey on spontaneous bilateral non-tumor ruptures of kidneys shows that over a 20-year period, only 3 cases of bilateral spontaneous ruptures have been reported. It is pointed out that panarteritis nodosa followed by hemorrhagic fever with renal syndrome is the commonest underlying cause of such ruptures. Clinically spontaneous ruptures become manifest with emergency condition presenting severe renal colic, impaired to serious general condition, often with acute abdomen and hemodynamic breakdown, and no past history evidence of renal disease or injury. In the initial phase diagnosing is not always easy; it is usually made on the ground of physical examination and the full range of imaging studies used in urological practice and during operative treatment. Emphasis is laid on the fact that the imaging methods are not invariably sufficient to identify the exact etiological factor giving rise to such a severe condition, but nevertheless these methods have an essential practical bearing on diagnosing a rupture. (authors)

  1. Surgical management of spontaneous hypertensive brainstem hemorrhage

    Directory of Open Access Journals (Sweden)

    Bal Krishna Shrestha

    2015-09-01

    Full Text Available Spontaneous hypertensive brainstem hemorrhage is the spontaneous brainstem hemorrhage associated with long term hypertension but not having definite focal or objective lesion. It is a catastrophic event which has a poor prognosis and usually managed conservatively. It is not uncommon, especially in eastern Asian populations, accounting approximately for 10% of the intracerebral hemorrhage. Before the advent of computed tomography, the diagnosis of brainstem hemorrhage was usually based on the clinical picture or by autopsy and believed to be untreatable via surgery. The introduction of computed tomography permitted to categorize the subtypes of brainstem hemorrhage with more predicted outcome. Continuous ongoing developments in the stereotactic surgery and microsurgery have added more specific surgical management in these patients. However, whether to manage conservatively or promptly with surgical evacuation of hematoma is still a controversy. Studies have shown that an accurate prognostic assessment based on clinical and radiological features on admission is critical for establishing a reasonable therapeutic approach. Some authors have advocate conservative management, whereas others have suggested the efficacy of surgical treatment in brainstem hemorrhage. With the widening knowledge in microsurgical techniques as well as neuroimaging technology, there seems to have more optimistic hope of surgical management of spontaneous hypertensive brainstem hemorrhage for better prognosis. Here we present five cases of severe spontaneous hypertensive brainstem hemorrhage patients who had undergone surgery; and explore the possibilities of surgical management in patients with the spontaneous hypertensive brainstem hemorrhage.

  2. Cursed lamp: the problem of spontaneous abortion.

    Science.gov (United States)

    Simkulet, William

    2017-08-09

    Many people believe human fetuses have the same moral status as adult human persons, that it is wrong to allow harm to befall things with this moral status, and thus voluntary, induced abortion is seriously morally wrong. Recently, many prochoice theorists have argued that this antiabortion stance is inconsistent; approximately 60% of human fetuses die from spontaneous abortion, far more than die from induced abortion, so if antiabortion theorists really believe that human fetuses have significant moral status, they have strong moral obligations to oppose spontaneous abortion. Yet, few antiabortion theorists devote any effort to doing so. Many prochoice theorists argue that to resolve this inconsistency, antiabortion theorists should abandon their opposition to induced abortion. Here, I argue that those who do not abandon their opposition to induced abortion but continue to neglect spontaneous abortion act immorally. Aristotle argues that moral responsibility requires both control and awareness; I argue that once an antiabortion theorist becomes aware of the frequency of spontaneous abortion, they have a strong moral obligation to redirect their efforts towards combating spontaneous abortion; failure to do so is morally monstrous. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Spontaneous Structuration of Hydrophobic Polymer Surfaces in Contact with Salt Solutions

    NARCIS (Netherlands)

    Sîretanu, Igor; Saadaoui, Hassan; Chapel, Jean Paul; Drummond, Carlos; Rodriguez-Hernandez, Juan; Drummond, Carlos

    2015-01-01

    It has been described in previous chapters how spontaneous instabilities related to interfacial phenomena can be used to produce controlled patterns on polymer surfaces. Strategies of polymer patterning assisted by dewetting or water drop condensation were described. In this chapter we present a

  4. Spontaneous Regression of Lumbar Herniated Disc

    Directory of Open Access Journals (Sweden)

    Chun-Wei Chang

    2009-12-01

    Full Text Available Intervertebral disc herniation of the lumbar spine is a common disease presenting with low back pain and involving nerve root radiculopathy. Some neurological symptoms in the majority of patients frequently improve after a period of conservative treatment. This has been regarded as the result of a decrease of pressure exerted from the herniated disc on neighboring neurostructures and a gradual regression of inflammation. Recently, with advances in magnetic resonance imaging, many reports have demonstrated that the herniated disc has the potential for spontaneous regression. Regression coincided with the improvement of associated symptoms. However, the exact regression mechanism remains unclear. Here, we present 2 cases of lumbar intervertebral disc herniation with spontaneous regression. We review the literature and discuss the possible mechanisms, the precipitating factors of spontaneous disc regression and the proper timing of surgical intervention.

  5. Spontaneous hemothorax: primary pleural epithelioid angiosarcoma

    Directory of Open Access Journals (Sweden)

    Amit Panjwani

    2016-01-01

    Full Text Available Spontaneous hemothorax is a rare condition seen in coagulation and vascular disorders. Uncommonly, malignant neoplasms may cause spontaneous hemothorax. Primary pleural epithelioid angiosarcomas (excluding the cases with pleuropulmonary or chest wall involvement are extremely rare pleural tumors, which may be mistaken for mesothelioma or adenocarcinoma, and only 19 cases (one of them from India have been reported in the English literature, to date. It commonly occurs in older men, has a nonspecific clinicoradiological presentation, and carries a poor prognosis with no survivors beyond a year of establishing the diagnosis. We report a case of primary pleural epithelioid angiosarcoma presenting as a life-threatening spontaneous hemothorax. We also present a brief literature review on pleural angiosarcoma.

  6. Computed tomographic findings of spontaneous intracranial hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seung Sook; Kim, Young Sook; Kim, Young Chul [College of Medicine, Chosun University, Kwangju (Korea, Republic of)

    1987-10-15

    Computed tomography (CT) was a reliable technique to evaluate the exact size and location of spontaneous intracranial hemorrhage and to predict it's prognosis. Fifty-nine cases of spontaneous intracranial hemorrhage were evaluated and reviewed by CT scan. The following results were obtained. 1. The sex ratio of male to female was 1 to 1.4, The highest incidence was in 6th and 7th decades. 2. The most common cause of spontaneous intracranial hemorrhage was hypertension (74.6%), followed by the aneurysm (13.5%), arteriovenous malformation (5.1%), occlusive vascular disease (3.4%), and blood dyscrasia (3.4%). 3. The most common location was basal ganglia and thalamic hemorrhage (37.3%), followed by lobar hemorrhage (27.1%), cerebellar hemorrhage (13.5%), and subarachnoid hemorrhage (11.9%). 4. Primary intraventricular hemorrhage carried the highest mortality. 5. The larger volume of hematoma, the higher the mortality rate.

  7. Spontaneous Perforation of Pyometra: A Case Report

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Pyometra is the accumulation of purulent material in the uterine cavity. Its reported incidence is 0.01–0.5% in gynecologic patients; however, as far as elderly patients are concerned, its incidence is 13.6% [3]. The most common cause of pyometra is malignant diseases of genital tract and the consequences of their treatment (radiotherapy. Other causes are benign tumors like leiomyoma, endometrial polyps, senile cervicitis, cervical occlusion after surgery, puerperal infections, and congenital cervical anomalies. Spontaneous rupture of the uterus is an extremely rare complication of pyometra. To our knowledge, only 21 cases of spontaneous perforation of pyometra have been reported in English literature since 1980. This paper reports an additional case of spontaneous uterine rupture.

  8. On spontaneous breakdown in Σ-models

    International Nuclear Information System (INIS)

    Ivanov, E.A.

    1975-01-01

    The group theory aspects of spontaneous breakdown in linear Σ-models are discussed. General conditions are formulated under which multiplet of group G (compact or noncompact) is suitable for constructing the Σ-model with a given subgroup of stability of vacuum. It is shown that the Σ-models of spontaneously broken space-time symmetries can be constructed in general only if some extra coordinates are introduced in addition to an ordinary 4-coordinate xsub(μ). The connection between Σ-models of internal symmetries and appropriate nonlinear realizations has also been investigated

  9. Two cases of spontaneous temporal encephalocele.

    Science.gov (United States)

    Kamiya, Kouhei; Mori, Harushi; Kunimatsu, Akira; Kawai, Kensuke; Usami, Kenichi; Ohtomo, Kuni

    2012-12-01

    This is a report of two cases of spontaneous temporal encephalocele: one was anteroinferior and presented with epilepsy; the other was posteroinferior and presented with facial neuritis and labyrinthitis. Spontaneous temporal encephalocele is relatively rare and apparently not familiar to a majority of primary physicians. It may present with a variety of symptoms according to its anatomical location, including cerebrospinal fluid fistulas, recurrent meningitis, chronic otitis media, hearing loss, facial nerve palsy and medically intractable epilepsy. Attention should be paid to this disease entity, as it is easily overlooked in imaging studies and can leave serious neurological deficits. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  11. Need for spontaneous breakdown of chiral symmetry

    International Nuclear Information System (INIS)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-01-01

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately

  12. Spontaneous subdural hematoma associated to Duret hemorrhage

    Directory of Open Access Journals (Sweden)

    William Alves Martins, MD

    2015-03-01

    Full Text Available Subdural hematoma (SH is a neurosurgical emergency, usually caused by head trauma. Non-traumatic causes include aneurysm or arterial–venous malformation rupture, coagulopathy and others. We report the case of a 66 year-old man who developed apparently unprovoked signs of increased intracranial pressure. Brain computed tomography scan showed an acute spontaneous SH, surgically treated. Throughout surgery, a ruptured cortical artery with intensive bleeding appeared and was cauterized. After surgery, patient remained comatose and a new CT demonstrated Duret hemorrhage at the brainstem. Acute spontaneous SH of arterial origin is rare and highly lethal, in which a good prognosis relies on early diagnosis and treatment.

  13. Primer on spontaneous heating and pyrophoricity

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    This primer was prepared as an information resource for personnel responsible for operation of DOE nuclear facilities. It has sections on combustion principles, spontaneous heating/ignition of hydrocarbons and organics, pyrophoric gases and liquids, pyrophoric nonmetallic solids, pyrophoric metals (including Pu and U), and accident case studies. Although the information in this primer is not all-encompassing, it should provide the reader with a fundamental knowledge level sufficient to recognize most spontaneous combustion hazards and how to prevent ignition and widespread fires. This primer is provided as an information resource only, and is not intended to replace any fire protection or hazardous material training.

  14. Cavity enhanced rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    A Williamson, Lewis; J Longdell, Jevon

    2014-01-01

    Amplified spontaneous emission is usually treated as an incoherent noise process. Recent theoretical and experimental work using rephasing optical pulses has shown that rephased amplified spontaneous emission (RASE) is a potential source of wide bandwidth time-delayed entanglement. Due to poor echo efficiency the plain RASE protocol does not in theory achieve perfect entanglement. Experiments done to date show a very small amount of entanglement at best. Here we show that RASE can, in principle, produce perfect multimode time-delayed two mode squeezing when the active medium is placed inside a Q-switched cavity. (paper)

  15. Spontaneous supersymmetry breaking on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Wenger, Urs [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2013-07-01

    We discuss various strategies for regularising supersymmetric quantum field theories on a space-time lattice. In general, simulations of lattice models with spontaneously broken supersymmetry suffer from a fermion sign problem related to the vanishing of the Witten index. We discuss a novel approach which evades this problem in low dimensions by formulating the path integral on the lattice in terms of fermion loops. Then we present exact results on the spectrum and the Witten index for N=2 supersymmetric quantum mechanics and results from simulations of the spontaneously broken N=1 Wess-Zumino model.

  16. Consumption of a dark roast coffee decreases the level of spontaneous DNA strand breaks: a randomized controlled trial.

    Science.gov (United States)

    Bakuradze, T; Lang, R; Hofmann, T; Eisenbrand, G; Schipp, D; Galan, J; Richling, E

    2015-02-01

    Coffee consumption has been reported to decrease oxidative damage in peripheral white blood cells (WBC). However, effects on the level of spontaneous DNA strand breaks, a well established marker of health risk, have not been specifically reported yet. We analyzed the impact of consuming a dark roast coffee blend on the level of spontaneous DNA strand breaks. Healthy men (n = 84) were randomized to consume daily for 4 weeks either 750 ml of fresh coffee brew or 750 ml of water, subsequent to a run in washout phase of 4 weeks. The study coffee was a blend providing high amounts of both caffeoylquinic acids (10.18 ± 0.33 mg/g) and the roast product N-methylpyridinium (1.10 ± 0.05 mg/g). Before and after the coffee/water consumption phase, spontaneous strand breaks were determined by comet assay. At baseline, both groups exhibited a similar level of spontaneous DNA strand breaks. In the intervention phase, spontaneous DNA strand breaks slightly increased in the control (water only) group whereas they significantly decreased in the coffee group, leading to a 27% difference within both arms (p = 0.0002). Food frequency questionnaires indicated no differences in the overall diet between groups, and mean body weight during the intervention phases remained stable. The consumption of the study coffee substantially lowered the level of spontaneous DNA strand breaks in WBC. We conclude that regular coffee consumption contributes to DNA integrity.

  17. Wheaten ferments spontaneous fermantation in biotechnological methods

    OpenAIRE

    KAKHRAMON SANOQULOVICH RAKHMONOV; ISABAEV ISMAIL BABADJANOVICH

    2016-01-01

    In article are shown results of research of biotechnological properties of wheaten leavens of spontaneous fermentation (in the example of pea-anisetree leaven) and their analysis. Also is established influence of the given type of leavens on the basic biopolymers of the flour, on the property of the pastry and quality of bread from wheaten flour.

  18. Original article Spontaneous Pregnancy Outcome after Surgical ...

    African Journals Online (AJOL)

    2011-09-28

    Sep 28, 2011 ... Table 2: Spontaneous pregnancy in relation to postoperative semen parameters. (no statistically significant difference), comparable to the mean ages of 22, 28.4 and. 34.9 years, respectively, reported by Bach et al9, Abdel- Meguid et al10 and Baazeem et al11. The mean age of the wives who did or did.

  19. Spontaneous symmetry breakdown in gauge theories

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1982-01-01

    The dynamical theory of spontaneous breakdown correctly predicts the bound states and relates the order parameters of electron-photon superconductivity and quark-gluon chiral symmetry. A similar statement cannot be made for the standard electro-weak gauge symmetry. (author)

  20. Identical Twin Primigravid Sisters -Spontaneous Labour and ...

    African Journals Online (AJOL)

    We report 2 cases of identical twin sisters, the older sibling getting married 14 months earlier but both got pregnant for their first child at about the same time and were managed by the same Obstetrician and fell into spontaneous labour within a few hours of each other. Both were delivered by emergency caesarean section ...

  1. SPONTANEOUS CP VIOLATION AND QUARK MASS AMBIGUITIES.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2004-09-21

    I explore the regions of quark masses where CP will be spontaneously broken in the strong interactions. The boundaries of these regions are controlled by the chiral anomaly, which manifests itself in ambiguities in the definition of non-degenerate quark masses. In particular, the concept of a single massless quark is ill defined.

  2. 1 INFLUENCE OF SPONTANEOUS FERMENTATION ON SOME ...

    African Journals Online (AJOL)

    RopSvr

    Spontaneous fermentation has been identified to improve the quality characteristics of foods derived from them. When combined with cowpea fortification and nixtamalization, it is expected to improve the nutritional, functional, physico-chemical and sensory qualities of maize based foods thereby improving the qualities as ...

  3. Association between Nutritional Status with Spontaneous Abortion

    Directory of Open Access Journals (Sweden)

    Rahimeh Ahmadi

    2016-11-01

    Full Text Available Background: Spontaneous abortion is the most common adverse pregnancy outcome. We aimed to investigate a possible link between nutrient deficiencies and the risk of spontaneous abortion. Materials and Methods: This case-control study included the case group (n=331 experiencing a spontaneous abortion before 14 weeks of pregnancy and the control group (n=331 who were healthy pregnant women over 14 weeks of pregnancy. The participants filled out Food Frequency Questionnaire (FFQ, in which they reported their frequency of consumption for a given serving of each food item during the past three months, on a daily, weekly or monthly basis. The reported frequency for each food item was converted to a daily intake. Then, consumption of nutrients was compared between the two groups. Results: There are significant differences between the two groups regarding consumed servings/day of vegetables, bread and cereal, meat, poultry, fish, eggs, beans, fats, oils and dairy products (P=0.012, P<0.001, P=0.004, P<0.001, P=0.019, respectively. There are significant differences between the two groups in all micronutrient including folic acid, iron, vitamin C, vitamin B6, vitamin B12 and zinc (P<0.001. Conclusion: Poor nutrientions may be correlated with increased risk of spontaneous abortion

  4. Spontaneous regression of an intraspinal disc cyst

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Eerens, I.; Wilms, G. [University Hospital, Leuven (Belgium). Dept. of Radiology; Goffin, J. [Dept. of Neurosurgery, University Hospitals, Leuven (Belgium)

    2001-11-01

    We present a patient with a so-called disc cyst. Its location in the ventrolateral epidural space and its communication with the herniated disc are clearly shown. The disc cyst developed rapidly and regressed spontaneously. This observation, which has not been reported until now, appears to support focal degeneration with cyst formation as the pathogenesis. (orig.)

  5. Spontaneous rupture of an infected renal cyst

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, W.; Toelly, E.; Ebner, F.; Kullnig, P.

    1986-07-01

    Spontaneous or traumatic rupture of renal cysts is a rare occurrence. The contents of the cyst can perforate into the renal calyx system or into the perirenal space. Perforation into the peritoneal cavity has also been described (1, 2, 4, 5).

  6. Proteomic Biomarkers for Spontaneous Preterm Birth

    DEFF Research Database (Denmark)

    Kacerovsky, Marian; Lenco, Juraj; Musilova, Ivana

    2014-01-01

    This review aimed to identify, synthesize, and analyze the findings of studies on proteomic biomarkers for spontaneous preterm birth (PTB). Three electronic databases (Medline, Embase, and Scopus) were searched for studies in any language reporting the use of proteomic biomarkers for PTB published...

  7. Spontaneous emission from saturated parametric amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Ott, Johan Raunkjær; Steffensen, Henrik

    2009-01-01

    Noise performance of parametric amplifiers is typically calculated assuming un-depleted operation. However, in many applications especially when applied as regenerative amplifiers in systems based on phase shift keyed modulation schemes, this assumption is not valid. Here we show the impact...... on accumulated spontaneous emission for a parametric amplifier operated in saturation....

  8. Spontaneous Non-verbal Counting in Toddlers

    Science.gov (United States)

    Sella, Francesco; Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

    2016-01-01

    A wealth of studies have investigated numerical abilities in infants and in children aged 3 or above, but research on pre-counting toddlers is sparse. Here we devised a novel version of an imitation task that was previously used to assess spontaneous focusing on numerosity (i.e. the predisposition to grasp numerical properties of the environment)…

  9. Editorial: Spontaneous bacterial peritonitis | Lule | East African ...

    African Journals Online (AJOL)

    Journal Home > Vol 81, No 3 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Editorial: Spontaneous bacterial peritonitis. GN Lule. Abstract. No Abstract Available. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT ...

  10. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  11. Spontaneous dimensional reduction in quantum gravity

    Science.gov (United States)

    Carlip, S.

    2016-07-01

    Hints from a number of different approaches to quantum gravity point to a phenomenon of “spontaneous dimensional reduction” to two spacetime dimensions near the Planck scale. I examine the physical meaning of the term “dimension” in this context, summarize the evidence for dimensional reduction, and discuss possible physical explanations.

  12. Surgical management of spontaneous ruptured hepatocellular adenoma

    Directory of Open Access Journals (Sweden)

    Marcelo Augusto Fontenelle Ribeiro Junior

    2009-01-01

    Full Text Available AIMS: Spontaneous ruptured hepatocellular adenoma (SRHA is a rare life-threatening condition that may require surgical treatment to control hemorrhaging and also stabilize the patient. We report a series of emergency surgeries performed at our institution for this condition. METHODS: We reviewed medical records and radiology files of 28 patients (from 1989 to 2006 with a proven diagnosis of hepatocellular adenoma (HA. Three (10.7% of 28 patients had spontaneous ruptured hepatocellular adenoma, two of which were associated with intrahepatic hemorrhage while one had intraperitoneal bleeding. Two patients were female and one was male. Both female patients had a background history of oral contraceptive use. Sudden abdominal pain associated with hemodynamic instability occurred in all patients who suffered from spontaneous ruptured hepatocellular adenoma. The mean age was 41.6 years old. The preoperative assessment included liver function tests, ultrasonography and computed tomography. RESULTS: The surgical approaches were as follows: right hemihepatectomy for controlling intraperitoneal bleeding, and right extended hepatectomy and non-anatomic resection of the liver for intrahepatic hemorrhage. There were no deaths, and the postoperative complications were bile leakage and wound infection (re-operation, as well as intraperitoneal abscess (re-operation and pleural effusion. CONCLUSION: Spontaneous ruptured hepatocellular adenoma may be treated by surgery for controlling hemorrhages and stabilizing the patient, and the decision to operate depends upon both the patient's condition and the expertise of the surgical team.

  13. Chronic Allium sativum administration alters spontaneous ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effects of Allium sativum extract on the medial prefrontal cortex and neurobehaviour of adult Wistar rats. ... altered spontaneous alternation, while cellular pathologic changes were observed in the medial prefrontal cortex of these test groups in a dose dependent sequence.

  14. Spontaneous hedonic reactions to social media cues

    NARCIS (Netherlands)

    Koningsbruggen, G.M. van; Hartmann, T.; Eden, A.; Veling, H.P.

    2017-01-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we

  15. Recurrent spontaneous intracerebral hemorrhage associated with ...

    African Journals Online (AJOL)

    Spontaneous intracerebral hemorrhage (ICH) accounts for 15% of stroke cases in the US and Europe and up to 30% in Asian populations. Intracerebral hemorrhage is a relatively uncommon form of stroke-it causes only 10 to 15 percent of all strokes. It is more disabling and has a higher mortality rate than ischemic stroke, ...

  16. Ovarian hyperstimulation syndrome in a spontaneous pregnancy ...

    African Journals Online (AJOL)

    It is known that most cases of Ovarian Hyperstimulation Syndrome (OHSS) are associated with the therapies for ovulation induction. However, OHSS may rarely be associated with a spontaneous ovulatory cycle, usually in the case of multiple gestations, hypothyroidism or polycystic ovary syndrome. We report a case of ...

  17. Spontaneous left main coronary artery dissection

    Directory of Open Access Journals (Sweden)

    Alptug Tokatli

    2016-03-01

    Full Text Available Spontaneous coronary artery dissection (SCAD is a very rare clinical condition. Physiopathology of SCAD is still mostly unclear. Clinical presentation of SCAD ranges from atypical symptoms to sudden cardiac death. The diagnosis of dissection is generally made by using conventional coronary angiography. Invasive or conservative treatment is reasonable.

  18. Spontaneous extracranial decompression of epidural hematoma

    International Nuclear Information System (INIS)

    Neely, John C.; Jones, Blaise V.; Crone, Kerry R.

    2008-01-01

    Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

  19. Spontaneous extracranial decompression of epidural hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Neely, John C. [Marshall University School of Medicine, Huntington, WV (United States); Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Crone, Kerry R. [Cincinnati Children' s Hospital Medical Center, Division of Neurosurgery, Cincinnati, OH (United States)

    2008-03-15

    Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

  20. Spontaneous Sourcing among Students Reading Multiple Documents

    Science.gov (United States)

    Stromso, Helge I.; Braten, Ivar; Britt, M. Anne; Ferguson, Leila E.

    2013-01-01

    This study used think-aloud methodology to explore undergraduates' spontaneous attention to and use of source information while reading six documents that presented conflicting views on a controversial social scientific issue in a Google-like environment. Results showed that students explicitly and implicitly paid attention to sources of documents…

  1. Massive Spontaneous Hemothorax, Giant Intrathoracic Meningocele ...

    African Journals Online (AJOL)

    haemothorax associated with von Recklinghausen's disease: Review of occurrence in Japan. Thorax 1997;52:575‑8. 3. Fedoruk LM, English J, Fradet GJ. Spontaneous hemothorax and neurofibromatosis: A review of a lethal combination. Asian Cardiovasc. Thorac Ann 2007;15:342‑4. 4. Conlon NP, Redmond KC, Celi LA.

  2. A Fatal Complication of Dermatomyositis: Spontaneous Pneumomediastinum

    Directory of Open Access Journals (Sweden)

    Ezgi Demirdöğen Çetinoğlu

    2016-04-01

    Full Text Available Interstitial lung disease (ILD is a negative prognostic factor associated with increased morbidity and mortality in patients with dermatomyositis (DM. Spontaneous pneumomediastinum is a rare complication of DM and it can be fatal. We present a 48-year-old woman with DM and ILD complicated by pneumomediastinum without pneumothorax and subcutaneous emphysema.

  3. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  4. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short ...

  5. Spontaneous Hedonic Reactions to Social Media Cues.

    Science.gov (United States)

    van Koningsbruggen, Guido M; Hartmann, Tilo; Eden, Allison; Veling, Harm

    2017-05-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we investigated less-frequent and frequent social media users' spontaneous hedonic reactions to social media cues using the Affect Misattribution Procedure-an implicit measure of affective reactions. Results demonstrated that frequent social media users showed more favorable affective reactions in response to social media (vs. control) cues, whereas less-frequent social media users' affective reactions did not differ between social media and control cues (Studies 1 and 2). Moreover, the spontaneous hedonic reactions to social media (vs. control) cues were related to self-reported cravings to use social media and partially accounted for the link between social media use and social media cravings (Study 2). These findings suggest that frequent social media users' spontaneous hedonic reactions in response to social media cues might contribute to their difficulties in resisting desires to use social media.

  6. Spontaneous electric fields in solid films: spontelectrics

    DEFF Research Database (Denmark)

    Field, David; Plekan, Oksana; Cassidy, Andrew

    2013-01-01

    When dipolar gases are condensed at sufficiently low temperature onto a solid surface, they form films that may spontaneously exhibit electric fields in excess of 108V/m. This effect, called the ‘spontelectric effect’, was recently revealed using an instrument designed to measure scattering...

  7. Spontaneous Retroperitoneal Hemorrhage from Adrenal Artery Aneurysm

    International Nuclear Information System (INIS)

    Gonzalez Valverde, F.M.; Balsalobre, M.; Torregrosa, N.; Molto, M.; Gomez Ramos, M.J.; Vazquez Rojas, J.L.

    2007-01-01

    Spontaneous adrenal hemorrhage is a very rare but serious disorder of the adrenal gland that can require emergent treatment. We report on a 42-year-old man who underwent selective angiography for diagnosis and treatment of retroperitoneal hemorrhage from small adrenal artery aneurysm. This case gives further details about the value of transluminal artery embolization in the management of visceral aneurysm rupture

  8. Individual differences in spontaneous analogical transfer.

    Science.gov (United States)

    Kubricht, James R; Lu, Hongjing; Holyoak, Keith J

    2017-05-01

    Research on analogical problem solving has shown that people often fail to spontaneously notice the relevance of a semantically remote source analog when solving a target problem, although they are able to form mappings and derive inferences when given a hint to recall the source. Relatively little work has investigated possible individual differences that predict spontaneous transfer, or how such differences may interact with interventions that facilitate transfer. In this study, fluid intelligence was measured for participants in an analogical problem-solving task, using an abridged version of the Raven's Progressive Matrices (RPM) test. In two experiments, we systematically compared the effect of augmenting verbal descriptions of the source with animations or static diagrams. Solution rates to Duncker's radiation problem were measured across varying source presentation conditions, and participants' understanding of the relevant source material was assessed. The pattern of transfer was best fit by a moderated mediation model: the positive impact of fluid intelligence on spontaneous transfer was mediated by its influence on source comprehension; however, this path was in turn modulated by provision of a supplemental animation via its influence on comprehension of the source. Animated source depictions were most beneficial in facilitating spontaneous transfer for those participants with low scores on the fluid intelligence measure.

  9. Spontaneous regression of a mandibular arteriovenous malformation

    Directory of Open Access Journals (Sweden)

    Scott B. Raymond, MD, PhD

    2015-06-01

    Full Text Available Mandibular arteriovenous malformations (AVMs are rare lesions that may initially present as catastrophic bleeding during dental surgical procedures. Owing to the significant risk of bleeding, most mandibular AVMs are treated definitively by resection or embolization. In this report, we describe a mandibular AVM that spontaneously regressed after biopsy.

  10. Unified gauge theories with spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    MacDowell, S.W.

    1975-01-01

    Unified gauge theories with spontaneous symmetry breaking are studied with a view to renormalize quantum field theory. Georgi-Glashow and Weinberg-Salam models to unify weak and electromagnetic interactions are discussed in detail. Gauge theories of strong interactions are also considered [pt

  11. Influence of spontaneous fermentation on some quality ...

    African Journals Online (AJOL)

    Spontaneous fermentation has been identified to improve the quality characteristics of foods derived from them. When combined with cowpea fortification and nixtamalization, it is expected to improve the nutritional, functional, physico- chemical and sensory qualities of maize based foods thereby improving the qualities as ...

  12. Maternal Factors Associated With Early Spontaneous Singleton ...

    African Journals Online (AJOL)

    Background: Knowledge of the maternal factors predisposing to preterm deliveries should affect the anticipatory care of mothers at risk of delivering preterm babies and improve perinatal outcome. Objective: To determine the maternal socio-biological characteristics associated with the delivery of early spontaneous ...

  13. PERIODIC-SOLUTIONS IN SPONTANEOUSLY BROKEN THEORIES

    NARCIS (Netherlands)

    BRIHAYE, Y; KUNZ, J

    A class of spontaneously broken field theories is proposed, and the occurrence of their periodic, classical solutions is investigated in detail. The emergence of multiple solutions is observed, their normal modes of oscillation are studied, and the bifurcations of the classical energy functional are

  14. Spontaneous sensorimotor coupling with multipart music.

    Science.gov (United States)

    Hurley, Brian K; Martens, Peter A; Janata, Petr

    2014-08-01

    Music often evokes spontaneous movements in listeners that are synchronized with the music, a phenomenon that has been characterized as being in "the groove." However, the musical factors that contribute to listeners' initiation of stimulus-coupled action remain unclear. Evidence suggests that newly appearing objects in auditory scenes orient listeners' attention, and that in multipart music, newly appearing instrument or voice parts can engage listeners' attention and elicit arousal. We posit that attentional engagement with music can influence listeners' spontaneous stimulus-coupled movement. Here, 2 experiments-involving participants with and without musical training-tested the effect of staggering instrument entrances across time and varying the number of concurrent instrument parts within novel multipart music on listeners' engagement with the music, as assessed by spontaneous sensorimotor behavior and self-reports. Experiment 1 assessed listeners' moment-to-moment ratings of perceived groove, and Experiment 2 examined their spontaneous tapping and head movements. We found that, for both musically trained and untrained participants, music with more instruments led to higher ratings of perceived groove, and that music with staggered instrument entrances elicited both increased sensorimotor coupling and increased reports of perceived groove. Although untrained participants were more likely to rate music as higher in groove, trained participants showed greater propensity for tapping along, and they did so more accurately. The quality of synchronization of head movements with the music, however, did not differ as a function of training. Our results shed new light on the relationship between complex musical scenes, attention, and spontaneous sensorimotor behavior.

  15. Socioeconomic position and the risk of spontaneous abortion

    DEFF Research Database (Denmark)

    Norsker, Filippa Nyboe; Espenhain, Laura; rogvi, Sofie

    2012-01-01

    To investigate the relationship between different indicators of socioeconomic position and the risk of spontaneous abortion.......To investigate the relationship between different indicators of socioeconomic position and the risk of spontaneous abortion....

  16. Spontaneous nematic alignment of a lipid nanotube in aqueous solutions.

    Science.gov (United States)

    Ding, Wuxiao; Minamikawa, Hiroyuki; Kameta, Naohiro; Wada, Momoyo; Masuda, Mitsutoshi; Shimizu, Toshimi

    2015-01-27

    The dispersibility and liquid crystal formation of a self-assembled lipid nanotube (LNT) was investigated in a variety of aqueous solutions. As the lipid component, we chose a bipolar lipid with glucose and tetraglycine headgroups, which self-assembled into an LNT with a small outer diameter of 16 to 17 nm and a high axial ratio of more than 310. The LNT gave a stable colloidal dispersion in its dilute solutions and showed spontaneous liquid crystal (LC) alignment at relatively low concentrations and in a pH region including neutral pH. The LNT samples with shorter length distributions were prepared by sonication, and the relationship between the LNT axial ratio and the minimum LC formation concentration was examined. The robustness of the LNT made the liquid crystal stable in mixed solvents of water/ethanol, water/acetone, and water/tetrahydrofuran (1:1 by volume) and at a temperature of up to 90 °C in water. The observed colloidal behavior of the LNT was compared to those of similar 1D nanostructures such as a phospholipid tubule.

  17. [Bacterial vaginosis and spontaneous preterm birth].

    Science.gov (United States)

    Brabant, G

    2016-12-01

    To determine if bacterial vaginosis is a marker for risk of spontaneous preterm delivery and if its detection and treatment can reduce this risk. Consultation of the database Pubmed/Medline, Science Direct, and international guidelines of medical societies. Bacterial vaginosis (BV) is a dysbiosis resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and jointly of a disappearance of well-known protective Lactobacilli. His diagnosis is based on clinical Amsel criteria and/or a Gram stain with establishment of the Nugent score. The prevalence of the BV extraordinarily varies according to ethnic and/or geographical origin (4-58 %), in France, it is close to 7 % in the first trimester of pregnancy (EL2). The link between BV and spontaneous premature delivery is low with an odds ratio between 1.5 and 2 in the most recent studies (EL3). Metronidazole or clindamycin is effective to treat BV (EL3). It is recommended to prescribe one of these antibiotics in the case of symptomatic BV (Professional Consensus). The testing associated with the treatment of BV in the global population showed no benefit in the prevention of the risk of spontaneous preterm delivery (EL2). Concerning low-risk asymptomatic population (defined by the absence of antecedent of premature delivery), it has been failed profit to track and treat the BV in the prevention of the risk of spontaneous preterm delivery (EL1). Concerning the high-risk population (defined by a history of preterm delivery), it has been failed profit to track and treat the VB in the prevention of the risk of spontaneous preterm delivery (EL3). However, in the sub population of patients with a history of preterm delivery occurred in a context of materno-fetal bacterial infection, there may be a benefit to detect and treat early and systematically genital infection, and in particular the BV (Professional Consensus). The screening and treatment of BV during pregnancy in asymptomatic low

  18. F. VON HAYEK’S THEORY OF SPONTANEOUS ORDER

    Directory of Open Access Journals (Sweden)

    О. Nesterenko

    2013-04-01

    Full Text Available The essence and the genesis of spontaneous order are disclosed in the context of critical analysis of constructivism. The author’s approach to the definition of the characteristic features of the spontaneous order is proposed. The dichotomy of the order is revealed towards the economic sphere in form of spontaneous order and organization.

  19. Solitary, spontaneous cervical and large bone fractures in aluminium osteodystrophy

    International Nuclear Information System (INIS)

    Sundaram, M.; Dessner, D.; Ballal, S.

    1991-01-01

    Aluminum-induced bone disease in uremic patients receiving dialysis was first described a little more than 10 years ago. The epidemic form of the disease was seen in centers where there was a high aluminum content in the water dialysate. Although this problem has been corrected, sporadic forms of the disease continue to be noted in dialyzed and nondialyzed patients. Multiple fractures are a radiological feature of aluminum-related bone disease. We present four patients whose nontraumatic fractures involved large bones, without evidence of multiple fractures. Healing was not seen in any of the fractures. In patients receiving dialysis the presence of spontaneous fractures of large bones or cervical vertebrae, which may be clinically silent or vaguely symptomatic, should raise the possibility of aluminum-induced osteomalacia even if these fractures are solitary. (orig./GDG)

  20. Maximum permissible concentration (MPC) values for spontaneously fissioning radionuclides

    International Nuclear Information System (INIS)

    Ford, M.R.; Snyder, W.S.; Dillman, L.T.; Watson, S.B.

    1976-01-01

    The radiation hazards involved in handling certain of the transuranic nuclides that exhibit spontaneous fission as a mode of decay were reaccessed using recent advances in dosimetry and metabolic modeling. Maximum permissible concentration (MPC) values in air and water for occupational exposure (168 hr/week) were calculated for 244 Pu, 246 Cm, 248 Cm, 250 Cf, 252 Cf, 254 Cf, /sup 254m/Es, 255 Es, 254 Fm, and 256 Fm. The half-lives, branching ratios, and principal modes of decay of the parent-daughter members down to a member that makes a negligible contribution to the dose are given, and all daughters that make a significant contribution to the dose to body organs following inhalation or ingestion are included in the calculations. Dose commitments for body organs are also given

  1. [Spontaneous renal artery dissection: a case report].

    Science.gov (United States)

    Maehana, Takeshi; Nishida, Sachiyo; Shindo, Tetsuya; Miyamoto, Shintaro; Muranaka, Takashi; Suzuki, Kazuhiro; Yanase, Masahiro

    2008-01-01

    A 65-year-old female was admitted to our hospital complaining of left upper abdominal pain. Although the symptom improved with observation, serum creatinine rose to 2.0 mg/dl. Slight atrophy of the left kidney was seen on abdominal plain computed tomography. In order to examine the possibility of renal infarction from thrombosis with angiography, we consulted the department of cardiovascular medicine. Even though we did not detect thrombosis with left renal angiography or intravascular ultrasound, there was a dissection finding localized at the left renal artery. Based on this finding, we made a diagnosis of spontaneous renal artery dissection and performed stent placement. Spontaneous renal artery dissection is extremely rare and the frequency of occurrence is reported to be less than 0.05%. Recently, however the frequency of detection has risen with the development of clinical imaging. We must keep in mind that the condition has the possibility of leading to renal blood circulation disorders.

  2. Thermal influences on spontaneous rock dome exfoliation

    Science.gov (United States)

    Collins, Brian D.; Stock, Greg M.; Eppes, Martha C.; Lewis, Scott W.; Corbett, Skye C.; Smith, Joel B.

    2018-01-01

    Rock domes, with their onion-skin layers of exfoliation sheets, are among the most captivating landforms on Earth. Long recognized as integral in shaping domes, the exact mechanism(s) by which exfoliation occurs remains enigmatic, mainly due to the lack of direct observations of natural events. In August 2014, during the hottest days of summer, a granitic dome in California, USA, spontaneously exfoliated; witnesses observed extensive cracking, including a ~8000 kg sheet popping into the air. Subsequent exfoliation episodes during the following two summers were recorded by instrumentation that captured—for the first time—exfoliation deformation and stress conditions. Here we show that thermal cycling and cumulative dome surface heating can induce subcritical cracking that culminates in seemingly spontaneous exfoliation. Our results indicate that thermal stresses—largely discounted in dome formation literature—can play a key role in triggering exfoliation and therefore may be an important control for shaping domes worldwide.

  3. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjøllund, Niels Henrik Ingvar; Jensen, T.K.; Bonde, J.P.

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... time periods are the relevant measure. We followed a cohort of first pregnancy planners from termination of birth control until pregnancy for a maximum of six menstrual cycles. The analyses include 181 pregnancies, of which 32 were subclinical pregnancies detected by hCG analysis only. During early...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  4. Spontaneous Enterocutaneous Fistula Resulting from Richter's Hernia.

    Science.gov (United States)

    Hajong, Ranendra; Khongwar, Donkupar; Komut, Ojing; Naku, Narang; Baru, Kappa

    2017-08-01

    Richter's hernia is due to the entrapment of a part of circumference of the bowel wall. As the bowel continuity is maintained, the patients usually do not have intestinal obstruction. Some patients with Richter's hernia may present with enterocutaneous fistula either spontaneous or due to surgical intervention mistaking the obstructed hernia to be inguinal abscess. This is more so in developing countries due to lack of awareness among the masses or due to the delay in seeking medical attention. Presenting here is a case of a 53-year-old male patient with enterocutaneous fistula which occurred spontaneously and sought medical attention only after about three years of repeated discharge of yellowish fluid from the left inguinal region. Magnetic resonance fistulogram confirmed the diagnosis of enterocutaneous fistula. Laparotomy with resection and primary anastomosis of the fistulous bowel was done. Patient recovered uneventfully without any complications or recurrence.

  5. Spontaneous Coronary Artery Dissection and Pregnancy.

    Science.gov (United States)

    Naderi, Sahar

    2017-09-01

    Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic, non-traumatic cause of coronary artery dissection. SCAD is the most common cause of myocardial infarction in pregnancy or the postpartum period and results in significant cardiovascular morbidity and mortality in the pregnant population. It is important to consider pregnancy-associated spontaneous coronary artery dissection (PASCAD) high on the differential for a pregnant woman who presents with symptoms consistent with acute coronary syndrome. Management of these patients requires a thoughtful, multidisciplinary approach, with consideration of conservative management if possible. Counseling regarding future pregnancies is also critical and requires compassionate care. Given our limited understanding of SCAD, including PASCAD, more data and research are needed to help guide diagnosis, management, and determination of prognosis.

  6. Spontaneous stress fractures of the femoral neck

    International Nuclear Information System (INIS)

    Dorne, H.L.; Lander, P.H.

    1985-01-01

    The diagnosis of spontaneous stress fractures of the femoral neck, a form of insufficiency stress fracture, can be missed easily. Patients present with unremitting hip pain without a history of significant trauma or unusual increase in daily activity. The initial radiographic features include osteoporosis, minor alterations of trabecular alignment, minimal extracortical or endosteal reaction, and lucent fracture lines. Initial scintigraphic examinations performed in three of four patients showed focal increased radionuclide uptake in two and no focal abnormality in one. Emphasis is placed on the paucity of early findings. Evaluation of patients with persistent hip pain requires a high degree of clinical suspicion and close follow-up; the sequelae of undetected spontaneous fractures are subcapital fracture with displacement, angular deformity, and a vascular necrosis of the femoral head

  7. Motivational Projections of Russian Spontaneous Speech

    Directory of Open Access Journals (Sweden)

    Galina M. Shipitsina

    2017-06-01

    Full Text Available The article deals with the semantic, pragmatic and structural features of words, phrases, dialogues motivation, in the contemporary Russian popular speech. These structural features are characterized by originality and unconventional use. Language material is the result of authors` direct observation of spontaneous verbal communication between people of different social and age groups. The words and remarks were analyzed in compliance with the communication system of national Russian language and cultural background of popular speech. Studies have discovered that in spoken discourse there are some other ways to increase the expression statement. It is important to note that spontaneous speech identifies lacunae in the nominative language and its vocabulary system. It is proved, prefixation is also effective and regular way of the same action presenting. The most typical forms, ways and means to update language resources as a result of the linguistic creativity of native speakers were identified.

  8. Spontaneous pneumomediastinum due to paralytic rabies

    Directory of Open Access Journals (Sweden)

    Wuping Wang

    2013-02-01

    Full Text Available Rabies is a fatal disease resulting from rabies virus infection, causing severe neurological symptoms and ultimately death by destroying the nervous system. In general, a patient tends to see a neurologist or an infectious diseases physician, with very common and typical discipline-related signs and symptoms, such as hydrophobia, aerophobia, and mental disorders. However, we reported a rabies patient who was first admitted to see a thoracic surgeon with spontaneous pneumomediastinum.

  9. Spontaneous pneumomediastinum due to paralytic rabies

    Directory of Open Access Journals (Sweden)

    Wuping Wang

    Full Text Available Rabies is a fatal disease resulting from rabies virus infection, causing severe neurological symptoms and ultimately death by destroying the nervous system. In general, a patient tends to see a neurologist or an infectious diseases physician, with very common and typical discipline-related signs and symptoms, such as hydrophobia, aerophobia, and mental disorders. However, we reported a rabies patient who was first admitted to see a thoracic surgeon with spontaneous pneumomediastinum.

  10. Self energy QED: Multipole spontaneous emission

    International Nuclear Information System (INIS)

    Salamin, Y.I.

    1990-08-01

    Within the context of Barut's self-field approach, we write the exact expression of the spontaneous atomic decay rate (Phys. Rev. A37, 2284 (1988)), in the long wavelength approximation, in terms of electric- and magnetic-like multipole contributions which are related to the matrix elements of the transition charge and current distributions of the relativistic electron. A number of features of these expressions are discussed and their generalization to interacting composite systems is also pointed out. (author). 8 refs

  11. Quantum mechanics with spontaneous localization and experiments

    International Nuclear Information System (INIS)

    Benatti, F.; Grassi, R.

    1994-05-01

    We examine from an experimental point of view the recently proposed models of spontaneous reduction. We compare their implications about decoherence with those of environmental effects. We discuss the treatment, within the considered models, of the so called quantum telegraph phenomenon and we show that, contrary to what has been recently stated, no problems are met. Finally, we review recent interesting work investigating the implications of dynamical reduction for the proton decay. (author). 16 refs, 4 figs, 3 tabs

  12. Spontaneous atlantoaxial subluxation associated with tonsillitis

    OpenAIRE

    Shunmugam, Meenalochani; Poonnoose, Santosh

    2015-01-01

    Atlantoaxial subluxation is a rare condition and requires a high index of suspicion to diagnose and treat in order to avoid long-term sequelae. Here, we present a case of late presentation of a nontraumatic rotatory subluxation of the atlantoaxial joint or atlantoaxial rotatory subluxation. A 17-year-old girl presented 3 months after the onset of nonspecific upper limb sensory symptoms which eventually settled spontaneously. Initial conservative management by the general practitioner had no e...

  13. Spontaneous Regression of a Cervical Disk Herniation

    Directory of Open Access Journals (Sweden)

    Emre Delen

    2014-03-01

    Full Text Available A 54 years old female patient was admitted to our outpatient clinic with a two months history of muscle spasms of her neck and pain radiating to the left upper extremity. Magnetic resonance imaging had shown a large left-sided paracentral disk herniation at the C6-C7 disk space (Figure 1. Neurological examination showed no obvious neurological deficit. She received conservative treatment including bed rest, rehabilitation, and analgesic drugs. After 13 months, requested by the patient, a second magnetic resonance imaging study showed resolution of the disc herniation.(Figure 2 Although the literature contains several reports about spontaneous regression of herniated lumbar disc without surgical intervention, that of phenomenon reported for herniated cervical level is rare, and such reports are few[1]. In conclusion, herniated intervertebral disc have the potential to spontaneously regress independently from the spine level. With further studies, determining the predictive signs for prognostic evaluation for spontaneous regression which would yield to conservative treatment would be beneficial.

  14. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  15. Spontaneous prediction error generation in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yuichi Yamashita

    Full Text Available Goal-directed human behavior is enabled by hierarchically-organized neural systems that process executive commands associated with higher brain areas in response to sensory and motor signals from lower brain areas. Psychiatric diseases and psychotic conditions are postulated to involve disturbances in these hierarchical network interactions, but the mechanism for how aberrant disease signals are generated in networks, and a systems-level framework linking disease signals to specific psychiatric symptoms remains undetermined. In this study, we show that neural networks containing schizophrenia-like deficits can spontaneously generate uncompensated error signals with properties that explain psychiatric disease symptoms, including fictive perception, altered sense of self, and unpredictable behavior. To distinguish dysfunction at the behavioral versus network level, we monitored the interactive behavior of a humanoid robot driven by the network. Mild perturbations in network connectivity resulted in the spontaneous appearance of uncompensated prediction errors and altered interactions within the network without external changes in behavior, correlating to the fictive sensations and agency experienced by episodic disease patients. In contrast, more severe deficits resulted in unstable network dynamics resulting in overt changes in behavior similar to those observed in chronic disease patients. These findings demonstrate that prediction error disequilibrium may represent an intrinsic property of schizophrenic brain networks reporting the severity and variability of disease symptoms. Moreover, these results support a systems-level model for psychiatric disease that features the spontaneous generation of maladaptive signals in hierarchical neural networks.

  16. Spontaneous Large Serous Retinal Pigment Epithelial Tear

    Directory of Open Access Journals (Sweden)

    Voraporn Chaikitmongkol

    2012-10-01

    Full Text Available Purpose: To report cases of spontaneous retinal pigment epithelial (RPE tear complicating serous pigment epithelial detachment (PED. Methods: The records of 3 Asian patients with spontaneous giant RPE tear were reviewed retrospectively by including clinical presentation, angiography, optical coherence tomography, fundus autofluorescence imaging, and visual outcome. Results: Three patients (4 eyes were included in this study, with a mean age of 48.3 (42–56 years, and a mean follow-up period of 7.75 (4–18 months. Fundus examination in all patients showed giant RPE tear associated with bullous PED. Two cases had a history of prior corticosteroid use, and 1 had no history of medication use. All 3 patients developed spontaneous resolution of subretinal fluid with no treatment. However, in patients who used corticosteroids, initial progression of the tear and subretinal fluid were observed despite ceasing medication. On subsequent follow-up, an incomplete RPE regeneration was demonstrated by fundus autofluorescence imaging, and choroidal neovascularization developed in 1 patient. Conclusion: Large PED with RPE tear is a rare manifestation. When the fovea is spared, visual prognosis is favorable. No specific treatment is required, but careful choroidal neovascularization monitoring should be performed.

  17. Spontaneous fission of the heaviest elements

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.C.

    1989-04-01

    Although spontaneous fission was discovered in /sup 238/U in 1940, detailed studies of the process were first made possible in the 1960's with the availability of milligram quantities of /sup 252/Cf. The advent of solid-state detectors made it possible to perform measurements of coincident fission fragments from even very short-lived spontaneous fission activities or those available in only very small quantities. Until 1971 it was believed that the main features of the mass and kinetic-energy distributions were essentially the same as those for thermal neutron-induced fission and that all low-energy fission proceeded via asymmetric mass division with total kinetic energies which could be derived by linear extrapolation from those of lighter elements. In 1971, measurements of /sup 257/Fm showed an increase in symmetric mass division with anomalously high TKE's. Subsequent experiments showed that in /sup 258/Fm and /sup 259/Fm, the most probable mass split was symmetric with very high total kinetic energy. Measurements for the heavier elements have shown symmetric mass distributions with both high and low total kinetic energies. Recent results for spontaneous fission properties of the heaviest elements are reviewed and compared with theory. 31 refs., 8 figs., 1 tab.

  18. Spontaneous Coronary Artery Dissection Associated With Pregnancy.

    Science.gov (United States)

    Tweet, Marysia S; Hayes, Sharonne N; Codsi, Elisabeth; Gulati, Rajiv; Rose, Carl H; Best, Patricia J M

    2017-07-25

    Spontaneous coronary artery dissection (SCAD) is the most common cause of pregnancy-associated myocardial infarction and remains poorly characterized. This study sought to assess presentation, clinical factors, and outcomes of pregnancy-associated spontaneous coronary artery dissection (P-SCAD) compared with spontaneous coronary artery dissection not associated with pregnancy (NP-SCAD). A Mayo Clinic registry was established in 2010 to include comprehensive retrospective and prospective SCAD data. Records were reviewed to identify women who were pregnant or ≤12 weeks postpartum at time of SCAD. Complete records were available for 323 women; 54 women met criteria for P-SCAD (4 during pregnancy) and they were compared with 269 women with NP-SCAD. Most events occurred within the first month postpartum (35 of 50). Compared with NP-SCAD, P-SCAD patients more frequently presented with ST-segment elevation myocardial infarction (57% vs. 36%; p = 0.009), left main or multivessel SCAD (24% vs. 5%; p vs. 14%; p = 0.0027, respectively), and left ventricular function ≤35% (26% vs. 10%; p = 0.0071). Among women with imaging of other vascular territories, P-SCAD was less likely with a diagnosis of fibromuscular dysplasia and extracoronary vascular abnormalities (42% vs. 64%; p = 0.047; and 46% vs. 77%; p = 0.0032, respectively). Compared with U.S. birth data, women with P-SCAD were more often multiparous (p = 0.0167), had a history of infertility therapies (p = 0.0004), and had pre-eclampsia (p = 0.001). On long-term follow-up (median 2.3 years) recurrent SCAD occurred in 51 patients, with no difference in the Kaplan Meier 5-year recurrence rates (10% vs. 23%; p = 0.18). P-SCAD patients had more acute presentations and high-risk features than women with NP-SCAD did. The highest frequency of P-SCAD occurred during the first postpartum month and P-SCAD patients less often had extracoronary vascular abnormalities. Hormonal, hemodynamic variations, and yet

  19. Keeping warm with fur in cold water: entrainment of air in hairy surfaces

    Science.gov (United States)

    Nasto, Alice; Regli, Marianne; Brun, Pierre-Thomas; Clanet, Christophe; Hosoi, Anette

    2015-11-01

    Instead of relying on a thick layer of body fat for insulation as many aquatic mammals do, fur seals and otters trap air in their dense fur for insulation in cold water. Using a combination of model experiments and theory, we rationalize this mechanism of air trapping underwater for thermoregulation. For the model experiments, hairy surfaces are fabricated using laser cut molds and casting samples with PDMS. Modeling the hairy texture as a network of capillary tubes, the imbibition speed of water into the hairs is obtained through a balance of hydrostatic pressure and viscous stress. In this scenario, the bending of the hairs and capillary forces are negligible. The maximum diving depth that can be achieved before the hairs are wetted to the roots is predicted from a comparison of the diving speed and imbibition speed. The amount of air that is entrained in hairy surfaces is greater than what is expected for classic Landau-Levich-Derjaguin plate plunging. A phase diagram with the parameters from experiments and biological data allows a comparison of the model system and animals.

  20. Multiple genetic switches spontaneously modulating bacterial mutability

    Directory of Open Access Journals (Sweden)

    Johnston Randal N

    2010-09-01

    Full Text Available Abstract Background All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations? Results To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability 'switching' among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution. Conclusions MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution.

  1. Being Spontaneous: The Future of Telehealth Implementation?

    Science.gov (United States)

    Mars, Maurice; Scott, Richard E

    2017-09-01

    The smartphone simplifies interprofessional communication, and smartphone applications can facilitate telemedicine activity. Much has been written about the steps that need to be followed to implement and establish a successful telemedicine service that is integrated into everyday clinical practice. A traditional and systematic approach has evolved incorporating activities such as strategy development, needs assessment, business cases and plans, readiness assessment, implementation plans, change management interventions, and ongoing monitoring and evaluation. This "best practice" has been promoted in the telehealth literature for many years. In contrast, several recent initiatives have arisen without any such formal undertakings. This article describes the strengths and weaknesses of two "spontaneous" telemedicine services in dermatology and burn management that have evolved in South Africa. Two spontaneous services were identified and reviewed. In one unsolicited service, doctors at rural referring hospitals have been taking photographs of skin lesions and sending them with a brief text message history to dermatologists using the instant messaging smartphone app, WhatsApp. In the other, burns service, admissions to the burns unit or the clinic were triaged by telephonic description of the case and completion of a preadmission questionnaire. More recently, management and referral decisions are made only after completion of the questionnaire and subsequent submission of photographs of the burn sent by WhatsApp, with the decision transmitted by text message. Although efficient and effective, potential legal and ethical shortcomings have been identified. These "spontaneous" telehealth services challenge traditional best practice, yet appear to lead to truly integrated practice and, therefore, are successful and warrant further study.

  2. Angyomatous vocal polypus: a complete spontaneous regression

    Directory of Open Access Journals (Sweden)

    Edmir Américo Lourenço

    Full Text Available The authors describe a male patient who had malignant lymphoma seven years ago which remitted with chemotherapy.Two years ago he developed dysphonia. An unilateral, pediculate smooth red lesion on the right vocal fold was later discovered. Even without benefit of medicamentosus treatment, the patient refused surgery. In a reevaluation using rigid telescopy of the larynx two years later, the lesion had disappeared, completely and spontaneously. As there are no existing publications on this topic, this case report is an alert that surgery should be recommended with extreme caution in this type of vocal disease.

  3. Cerebrovascular gene expression in spontaneously hypertensive rats

    DEFF Research Database (Denmark)

    Grell, Anne-Sofie; Frederiksen, Simona Denise; Edvinsson, Lars

    2017-01-01

    in the middle cerebral arteries from hypertensive compared to normotensive rats. The gene expression of 72 genes was decreased and the gene expression of 97 genes was increased. The following genes with a fold difference ≥1.40 were verified by quantitative PCR; Postn, Olr1, Fas, Vldlr, Mmp2, Timp1, Serpine1......, Mmp11, Cd34, Ptgs1 and Ptgs2. The gene expression of Postn, Olr1, Fas, Vldlr, Mmp2, Timp1 and Serpine1 and the protein expression of LOX1 (also known as OLR1) were significantly increased in the middle cerebral arteries from spontaneously hypertensive rats compared to Wistar-Kyoto rats. In conclusion...

  4. Spontaneous light emission from fibers in MINOS

    International Nuclear Information System (INIS)

    Avvakumov, S.; Barrett, W.L.; Belias, T.; Bower, C.; Erwin, A.; Kordosky, M.; Lang, K.; Lee, R.; Liu, J.; Miller, W.; Mualem, L.; Nichol, R.; Nelson, J.; Pearce, G.; Proga, M.; Rebel, B.; Ruddick, K.; Smith, C.; Thomas, J.; Vahle, P.; Webb, R.

    2005-01-01

    We report on the observation and measurements of unexpected background rates in the MINOS Far Detector. The noise level at the Far Detector is significantly greater than that expected from natural radioactivity and intrinsic photomultiplier dark current. We have conducted a series of additional tests which demonstrate that the excess rate is caused by spontaneous light emission in the wavelength-shifting fibers, which are used to read out signals from scintillator strips. This noise due to fibers exhibits an exponential fall off with time with a decay time constant of the order of 100 days

  5. Fracture of maternal sternum during spontaneous delivery.

    Science.gov (United States)

    Stubert, J; Gerber, B

    2009-12-01

    We report of a maternal sternal fracture during a spontaneous delivery in a 31-year-old primipara without a suitable trauma. The putative mechanism of fracture was strong hyperflexion of the thoracic spine and additional cervical flexion with pushing the chin to the thorax due to active management of labour. The history of the healthy woman was free of related risk factors. A possible promoting factor might be pregnancy-induced bone loss. Although there were clear symptoms, the diagnosis of the fracture was delayed by a week because nobody took account of such a possibility.

  6. Modeling Residual NAPL in Water-Wet Porous Media

    Directory of Open Access Journals (Sweden)

    R.J. Lenhard

    2002-06-01

    Full Text Available A model is outlined that predicts NAPL which is held in pore wedges and as films or lenses on solid and water surfaces and contributes negligibly to NAPL advection. This is conceptually referred to as residual NAPL. Since residual NAPL is immobile, it remains in the vadose zone after all free NAPL has drained. Residual NAPL is very important because it is a long-term source for groundwater contamination. Recent laboratory experiments have demonstrated that current models for predicting subsurface NAPL behavior are inadequate because they do not correctly predict residual NAPL. The main reason for the failure is a deficiency in the current constitutive theories for multiphase flow that are used in numerical simulators. Multiphase constitutive theory governs the relations among relative permeability, saturation, and pressure for fluid systems (i.e., air, NAPL, water. In this paper, we outline a model describing relations between fluid saturations and pressures that can be combined with existing multiphase constitutive theory to predict residual NAPL. We test the revised constitutive theory by applying it to a scenario involving NAPL imbibition and drainage, as well as water imbibition and drainage. The results suggest that the revised constitutive theory is able to predict the distribution of residual NAPL in the vadose zone as a function of saturation-path history. The revised model describing relations between fluid saturation and pressures will help toward developing or improving numerical multiphase flow simulators.

  7. Numerical analysis of a three-phase system with a fluctuating water table

    International Nuclear Information System (INIS)

    White, M.D.; Lenhard, R.J.

    1993-03-01

    Numerical simulations are presented of a one-dimensional, multiphase flow system that involves the redistribution of aqueous-phase liquids and nonaqueous-phase liquids (NAPLs) by a fluctuating water table. The numerical analyses were completed using an integrated-volume, finite-difference-based solution scheme of the governing multiphase conservation equations and constitutive theory. Conservation equations were solved for two components water and oil, with the assumption of a passive gas-phase. Nonlinearities introduced into the governing conservation equations through the constitutive theory were handled with a multivariable Newton-Raphson iterative scheme. The functional relationships between the phase relative permeability, the phase saturation, and phase pressures in porous media were described with a general theoretical model that includes the effects of air and oil occlusion during imbibition. Parameters required for the theoretical model were defined for two-phase systems (e.g., air- water, air-oil, and oil-water). The theoretical model assumes that wettability decreases in the following order: water, oil, air. Results from the numerical simulations are compared against measurements taken from a previous multiphase flow experiment. The experiment involved subjecting an initially water-drained, three-phase system (i.e., air-oil-water), to a fluctuating water table. The experimental objective was to quantify the entrapment of air and NAPL by phases of greater wettability under dynamic conditions. Comparison of numerical and experimental results were made for two ratios of imbibition to drainage characteristic, curve-shape parameters and two models for relative permeability in two-phase systems. A description of the numerical methods used to solve the governing conservation and constitutive equations for multiphase hysteretic conditions is given

  8. Tilting oil-water contact in the chalk of Tyra Field as interpreted from capillary pressure data

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Rana, M.A.

    2010-01-01

    -trends from logs were compared with normalized water saturation depth-trends predicted from capillary pressure core data. The ten wells lie close to a SW–NE cross section of the field. For the gas–oil contact, a free contact measured in one well corresponds to a practically horizontal contact interpreted from...... of imbibition, where the free water level overlies an interval of residual oil, whereas in the eastern part of the field, the depth-wise trends in normalized water saturation correspond to a situation of drainage. The free water level apparently dips to the east due either to hydrodynamic action or to pressure......The Tyra Field in the central North Sea is located in Palaeogene and Upper Cretaceous chalk. It contains a natural gas zone underlain by an oil leg. Based on analysis of logs and core data from ten wells drilled prior to the field being put into production, normalized water saturation depth...

  9. Spontaneous cooperation for prosocials, but not for proselfs: Social value orientation moderates spontaneous cooperation behavior

    Science.gov (United States)

    Mischkowski, Dorothee; Glöckner, Andreas

    2016-01-01

    Cooperation is essential for the success of societies and there is an ongoing debate whether individuals have therefore developed a general spontaneous tendency to cooperate or not. Findings that cooperative behavior is related to shorter decision times provide support for the spontaneous cooperation effect, although contrary results have also been reported. We show that cooperative behavior is better described as person × situation interaction, in that there is a spontaneous cooperation effect for prosocial but not for proself persons. In three studies, one involving population representative samples from the US and Germany, we found that cooperation in a public good game is dependent on an interaction between individuals’ social value orientation and decision time. Increasing deliberation about the dilemma situation does not affect persons that are selfish to begin with, but it is related to decreasing cooperation for prosocial persons that gain positive utility from outcomes of others and score high on the related general personality trait honesty/humility. Our results demonstrate that the spontaneous cooperation hypothesis has to be qualified in that it is limited to persons with a specific personality and social values. Furthermore, they allow reconciling conflicting previous findings by identifying an important moderator for the effect. PMID:26876773

  10. Crocin loaded nano-emulsions: Factors affecting emulsion properties in spontaneous emulsification.

    Science.gov (United States)

    Mehrnia, Mohammad-Amin; Jafari, Seid-Mahdi; Makhmal-Zadeh, Behzad S; Maghsoudlou, Yahya

    2016-03-01

    Spontaneous emulsification may be used for encapsulating bioactive compounds in food and pharmaceutical industry. It has several advantages over high energy and other low energy methods including, protecting sensitive compounds against severe conditions of high energy method and its ability to minimize surfactant, removal of cosurfactant and thermal stability compared with other low energy methods. In this study, we examined possibility of encapsulating highly soluble crocin in W/O micro-emulsions using spontaneous method which further could be used for making double emulsions. Nonionic surfactants of Span 80 and polyglycerol polyricinoleate (PGPR) were used for making micro-emulsions that showed the high potential of PGPR for spontaneous method. Surfactant to water ratio (SWR%) was evaluated to find the highest amount of aqueous phase which can be dispersed in organic phase. Droplet size decreased by increasing SWR toward the SWR=100% which had the smallest droplet size and then increased at higher levels of surfactant. By increasing SWR, shear viscosity increased which showed the high effect of PGPR on rheological properties. This study shows in addition to W/O micro-emulsions, spontaneous method could be used for preparing stable O/W micro-emulsions. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Spontaneous regression of intracranial malignant lymphoma

    International Nuclear Information System (INIS)

    Kojo, Nobuto; Tokutomi, Takashi; Eguchi, Gihachirou; Takagi, Shigeyuki; Matsumoto, Tomie; Sasaguri, Yasuyuki; Shigemori, Minoru.

    1988-01-01

    In a 46-year-old female with a 1-month history of gait and speech disturbances, computed tomography (CT) demonstrated mass lesions of slightly high density in the left basal ganglia and left frontal lobe. The lesions were markedly enhanced by contrast medium. The patient received no specific treatment, but her clinical manifestations gradually abated and the lesions decreased in size. Five months after her initial examination, the lesions were absent on CT scans; only a small area of low density remained. Residual clinical symptoms included mild right hemiparesis and aphasia. After 14 months the patient again deteriorated, and a CT scan revealed mass lesions in the right frontal lobe and the pons. However, no enhancement was observed in the previously affected regions. A biopsy revealed malignant lymphoma. Despite treatment with steroids and radiation, the patient's clinical status progressively worsened and she died 27 months after initial presentation. Seven other cases of spontaneous regression of primary malignant lymphoma have been reported. In this case, the mechanism of the spontaneous regression was not clear, but changes in immunologic status may have been involved. (author)

  12. Spontaneous bending of pre-stretched bilayers.

    Science.gov (United States)

    DeSimone, Antonio

    2018-01-01

    We discuss spontaneously bent configurations of pre-stretched bilayer sheets that can be obtained by tuning the pre-stretches in the two layers. The two-dimensional nonlinear plate model we use for this purpose is an adaptation of the one recently obtained for thin sheets of nematic elastomers, by means of a rigorous dimensional reduction argument based on the theory of Gamma-convergence (Agostiniani and DeSimone in Meccanica. doi:10.1007/s11012-017-0630-4, 2017, Math Mech Solids. doi:10.1177/1081286517699991, arXiv:1509.07003, 2017). We argue that pre-stretched bilayer sheets provide us with an interesting model system to study shape programming and morphing of surfaces in other, more complex systems, where spontaneous deformations are induced by swelling due to the absorption of a liquid, phase transformations, thermal or electro-magnetic stimuli. These include bio-mimetic structures inspired by biological systems from both the plant and the animal kingdoms.

  13. Surgery for spontaneous intracerebral hemorrhage: Emerging trends

    Directory of Open Access Journals (Sweden)

    Girish Menon

    2017-01-01

    Full Text Available In spite of advances in imaging and surgical techniques, spontaneous intracerebral hemorrhage (SICH has defied attempts to find a scientifically proven effective therapy. The pathophysiology of SICH suggests that early removal of the clot with minimal additional surgical trauma should prove beneficial. Trials in this direction have been few, and for some unknown reason, surgery has not proved to be superior to best medical management in most of these trials. This has led to substantial variability in the management of ICH throughout the world, and the treatment of SICH remains a controversy. SICH encompasses spectra of possible clot locations with varying volumes. Surgery so far has been reserved only for patients with large hematomas and impending brain herniation. Critical analysis of the earlier studies has now shown that surgery does help in clots in certain locations and of particular volume and when done at an optimal time. Poor grade patients with large hematomas, earlier considered poor surgical candidates are being taken up for aggressive decompressive craniectomies with fair results. In addition, minimally invasive surgical techniques complemented by thrombolytic techniques seem to providing surprisingly good results. Overall surgery seems to be going through a period of renaissance with respect to primary spontaneous ICHs.

  14. Spontaneous unscheduled DNA synthesis in human lymphocytes

    International Nuclear Information System (INIS)

    Forell, B.; Myers, L.S. Jr.; Norman, A.

    1979-01-01

    The rate of spontaneous unscheduled DNA synthesis in human lymphocytes was estimated from measurements of tritiated thymidine incorporation into double-stranded DNA (ds-DNA) during incubation of cells in vitro. The contribution of scheduled DNA synthesis to the observed incorporation was reduced by inhibiting replication with hydroxyurea and by separating freshly replicated single-stranded DNA (ss-DNA) from repaired ds-DNA by column chromatography. The residual contribution of scheduled DNA synthesis was estimated by observing effects on thymidine incorporation of: (a) increasing the rate of production of apurinic sites, and alternatively, (b) increasing the number of cells in S-phase. Corrections based on estimates of endogenous pool size were also made. The rate of spontaneous unscheduled DNA synthesis is estimated to be 490 +- 120 thymidine molecules incorporated per cell per hour. These results compare favorably with estimates made from rates of depurination and depyrimidination of DNA, measured in molecular systems if we assume thymidine is incorporated by a short patch mechanism which incorporates an average of four bases per lesion

  15. Spontaneous ad hoc mobile cloud computing network.

    Science.gov (United States)

    Lacuesta, Raquel; Lloret, Jaime; Sendra, Sandra; Peñalver, Lourdes

    2014-01-01

    Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

  16. Spontaneous and stimulated emission from quasifree electrons

    Science.gov (United States)

    Friedman, A.; Gover, A.; Kurizki, G.; Ruschin, S.; Yariv, A.

    1988-04-01

    This article presents a unified formulation and review of an extensive class of radiation effects and devices based on free or quasifree electrons. The effects and devices reviewed include slow-wave radiators [such as Čerenkov, Smith-Purcell, and TWT (traveling-wave tube) effects and devices], periodic bremsstrahlung radiators [such as undulator radiation, magnetic bremsstrahlung FEL's (free-electron lasers), and coherent bremsstrahlung in the crystal lattice], and transverse-binding radiators [such as the CRM (cyclotron resonance maser) and channeling radiation]. Starting from a general quantum-electrodynamic model, both quantum and classical effects and operating regimes of these radiation devices are described. The article provides a unified physical description of the interaction kinematics, and presents equations for the characterization of spontaneous and stimulated radiative emission in these various effects and devices. Universal relations between the spontaneous and stimulated emission parameters are revealed and shown to be related (in the quantum limit) to Einstein relations for atomic radiators and (in the classical limit) to the relations derived by Madey for magnetic bremsstrahlung FEL for on-axis radiative emission. Examples for the application of the formulation are given, estimating the feasibility of channeling radiation x-ray laser and optical regime Smith-Purcell FEL, and deriving the gain equations of magnetic bremsstrahlung FEL and CRM for arbitrary electron propagation direction, structure (wiggler) axis, and radiative emission angle.

  17. Progesterone to prevent spontaneous preterm birth

    Science.gov (United States)

    Romero, Roberto; Yeo, Lami; Chaemsaithong, Piya; Chaiworapongsa, Tinnakorn; Hassan, Sonia

    2014-01-01

    Summary Preterm birth is the leading cause of perinatal morbidity and mortality worldwide, and its prevention is an important healthcare priority. Preterm parturition is one of the ‘great obstetrical syndromes’ and is caused by multiple etiologies. One of the mechanisms of disease is the untimely decline in progesterone action, which can be manifested by a sonographic short cervix in the midtrimester. The detection of a short cervix in the midtrimester is a powerful risk factor for preterm delivery. Vaginal progesterone can reduce the rate of preterm delivery by 45%, and the rate of neonatal morbidity (admission to neonatal intensive care unit, respiratory distress syndrome, need for mechanical ventilation, etc.). To prevent one case of spontaneous preterm birth birth in women with a short cervix both with and without a prior history of preterm birth. In patients with a prior history of preterm birth, vaginal progesterone is as effective as cervical cerclage to prevent preterm delivery. 17α-Hydroxyprogesterone caproate has not been shown to be effective in reducing the rate of spontaneous preterm birth in women with a short cervix. PMID:24315687

  18. Microchimerism after induced or spontaneous abortion.

    Science.gov (United States)

    Sato, Tomoko; Fujimori, Keiya; Sato, Akira; Ohto, Hitoshi

    2008-09-01

    To investigate fetomaternal microchimerism in women with induced abortion or spontaneous pregnancy loss. Peripheral blood samples were obtained from 76 healthy women who underwent dilation and curettage in the first trimester but had never had an abortion or male delivery before. Samples were collected at three time points: just before, 7 days after, and 30 days after abortion. Y chromosome-specific, nested polymerase chain reaction targeting the sex-determining region of Y (SRY) was used to test DNA extracted from buffy coat cells. DNA was also extracted from the chorion to determine sex. The sensitivity of our assay allowed detection of approximately one male cell in 100,000 female cells. Thirty-six male and 40 female chorions were obtained. Male DNA was found in 52.8% of women who had a male chorion before abortion, decreasing to 5.6% at 7 days after abortion. At 30 days after abortion, no male DNA was detected. Male DNA was never detected at any point from women with a female chorion. Fetal cells in the maternal circulation are undetectable 30 days after induced abortion or spontaneous pregnancy loss. Fetal cells may be harbored in maternal organs.

  19. Body Mass Index and spontaneous miscarriage.

    LENUS (Irish Health Repository)

    Turner, Michael J

    2012-02-01

    OBJECTIVE: We compared the incidence of spontaneous miscarriage in women categorised as obese, based on a Body Mass Index (BMI) >29.9 kg\\/m(2), with women in other BMI categories. STUDY DESIGN: In a prospective observational study conducted in a university teaching hospital, women were enrolled at their convenience in the first trimester after a sonogram confirmed an ongoing singleton pregnancy with fetal heart activity present. Maternal height and weight were measured digitally and BMI calculated. Maternal body composition was measured by advanced bioelectrical impedance analysis. RESULTS: In 1200 women, the overall miscarriage rate was 2.8% (n=33). The mean gestational age at enrolment was 9.9 weeks. In the obese category (n=217), the miscarriage rate was 2.3% compared with 3.3% in the overweight category (n=329), and 2.3% in the normal BMI group (n=621). There was no difference in the mean body composition parameters, particularly fat mass parameters, between those women who miscarried and those who did not. CONCLUSIONS: In women with sonographic evidence of fetal heart activity in the first trimester, the rate of spontaneous miscarriage is low and is not increased in women with BMI>29.9 kg\\/m(2) compared to women in the normal BMI category.

  20. Brain MRI findings of spontaneous intracranial hypotension

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Kyu; Byun, Woo Mok; Cho, Jae Ho; Cho Kil Ho; Hwang, Mi Soo; Park, Bok Hwan [Yeungnam Univ. College of Medicine, Taegu (Korea, Republic of); Joo, Yang Gu [Keimyoung Univ. College of Medicine, Taegu (Korea, Republic of); Lee, Sang Jin [Soonchunhyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-09-01

    To evaluate brain MRI findings of spontaneous intracranial hypotension. A retrospective review of MRI findings was conducted on six patients with clinically proven spontaneous intracranial hypotension; no patient had a history of previous spinal puncture. Follow-up MRI was available in two patients, and to detect CSF leakage, radio-nuclide cisternography(n=3D5), myelography(n=3D1), and MR myelography(n=3D1) were performed. On contrast-enhanced T1WI, diffuse dural enhancement was seen in all cases, subdural hematoma or hygroma was seen in four cases, pituitary gland prominence in four, dural sinus dilatation in four, downward displacement of the cerebellar tonsil in two, downward displacement of the iter in one, and suprasellar and prepontine cistern effacement in two. In no patient was abnormal CSF leakage found. Although dural enhancement, as seen on MRI, is not specific, diffuse enhancement of the dura mater accompanied by subdural hematoma, hygroma, pituitary gland prominence, dural sinus dilatation, downward displacement of the cerebellar tonsil, or suprasellar and prepontine cistern effacement can strongly suggest intracranial hypotension.=20.

  1. Maternal smoking predicts the risk of spontaneous abortion

    DEFF Research Database (Denmark)

    Nielsen, Ann; Hannibal, Charlotte Gerd; Lindekilde, Bodil Eriksen

    2006-01-01

    BACKGROUND: Few studies have examined smoking prior to pregnancy and the occurrence of spontaneous abortion, as most studies have addressed the risk of spontaneous abortion in relation to smoking during pregnancy. However, results are not entirely consistent. The aim of the present study...... was to assess the risk of spontaneous abortion considering smoking prior to pregnancy. METHODS: We performed a nested case-control study using prospective data from a population-based cohort comprising 11,088 women aged 20-29 years. From this cohort, women who experienced either a spontaneous abortion (n=343......) or who gave birth (n=1,578) during follow-up were selected. Associations between self-reported smoking at enrollment and subsequent spontaneous abortion were analyzed by means of multiple logistic regression. RESULTS: The risk of spontaneous abortion in relation to pre-pregnancy smoking showed a clear...

  2. Maternal underweight and the risk of spontaneous abortion

    DEFF Research Database (Denmark)

    Helgstrand, Stine; Andersen, Anne-Marie Nybo

    2005-01-01

    BACKGROUND: To evaluate the risk of spontaneous abortion in relation to maternal pre-pregnant underweight. METHODS: The study was designed as a cohort study within the framework of the Danish National Birth Cohort (DNBC). The participants were a total of 23 821 women recruited consecutively...... spontaneous abortion. Relative risk of spontaneous abortion was calculated as Hazard Ratios using Cox regression with delayed entry. RESULTS: The outcome measure was spontaneous abortion. The hazard ratio for spontaneous abortion in women with a pre-pregnant body mass index (BMI) below 18.5 was 1.24 (95......% confidence limits 0.95-1.63) compared to women with pre-pregnant BMI 18.5-24.9. Women with a BMI of 25 or more had a smaller increase in risk of spontaneous abortion. Adjustment for maternal age, parity, previous miscarriages, and lifestyle factors did not affect the estimates substantially, neither did...

  3. Spontaneous resolution of a herniated fragment cervical disc

    OpenAIRE

    METE, Mesut; SAVRAN, Mehmet; DEMİRÇİVİ ÖZER, Füsun; DURANSOY, Yusuf Kurtuluş

    2012-01-01

    ABSTRACT Although the spontaneous resolution of herniated nucleus pulposus is a well known phe¬nomenon in lumbar disc herniations, it is rarely encountered in the cervical region. The spontaneous resolution of a herniated cervical disc in a woman is reported to describe a rare occurrence of spontaneous regression of a cervical herniated nucleus pulposus and to discuss its mechanism. A woman with a large and fragment herniated cervical disc refused to undergo operation and was followed-up ...

  4. Spontaneous globe luxation associated with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    M Ashok Kumar

    2012-01-01

    Full Text Available Spontaneous globe luxation is a rarely reported condition which can lead to complications like optic neuropathy. Common causes are thyroid eye disease, shallow orbit and floppy eyelid syndrome. We report a case of spontaneous globe luxation with the onset and severity associated with chronic obstructive pulmonary disease (COPD. To our knowledge, this is the first case of spontaneous globe luxation associated with COPD.

  5. Biomarkers of Spontaneous Recovery from Traumatic Spinal Cord Injury

    Science.gov (United States)

    2017-10-01

    inflammation. 15. SUBJECT TERMS traumatic spinal cord injury, spinal cord , spontaneous recovery, functional recovery, inflammation, biomarkers, trauma 16...Award Number: W81XWH-15-1-0614 TITLE: Biomarkers of Spontaneous Recovery from Traumatic Spinal Cord Injury PRINCIPAL INVESTIGATOR: Ona Bloom...SUBTITLE 5a. CONTRACT NUMBER W81XWH-15-1-0614 W81XWH-15-1-0614 Biomarkers of Spontaneous Recovery from Traumatic Spinal Cord Injury 5b. GRANT NUMBER

  6. Effects of Electrolyte on Floating Water Bridge

    Directory of Open Access Journals (Sweden)

    Hideo Nishiumi

    2009-01-01

    spontaneously. In this paper, we examined flow direction of water bridge and what effects the addition of electrolytes such as NaCl, NaOH, and NH4Cl to the floating water bridge would give. We found that ionization degree reduced the length of water bridge though insoluble electrolyte Al2O3 had no effect on the length of water bridge.

  7. Spontaneous regression of a lumbar disc herniation: case report

    Directory of Open Access Journals (Sweden)

    Mostarchid Brahim El

    2016-12-01

    Full Text Available Lumbar disc herniation is a common disease that induces back pain and radicular pain. Some cases require conservative treatment or at times relived spontaneously. Spontaneous regression of disc herniation is an atypical clinical presentation, and it has been recognized with the advancement of recent advances in imaging techniques. We present a 35-year-old woman presented a spontaneous regression of a lumbar disc herniation with good outcome after intensive physical therapy program. Spontaneous regression of disc herniation is thought to occur via an inflammatory reaction with molecular mechanisms of phagocytic processes.

  8. Spontaneous closure of an ileostomy: A rare occurrence

    Directory of Open Access Journals (Sweden)

    Ashish Saxena

    2015-01-01

    CONCLUSION: Further research is warranted to understand the mechanism behind spontaneous regression of a stoma. Relationship between this event and intestinal tuberculosis or ATT needs to be analysed.

  9. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases......; this report is the first to document complete spontaneous regression of cerebral metastases from malignant melanoma by means of computed tomography scans. Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour in the absence of all treatment or in the presence...

  10. Dorsomedial prefontal cortex supports spontaneous thinking per se.

    Science.gov (United States)

    Raij, T T; Riekki, T J J

    2017-06-01

    Spontaneous thinking, an action to produce, consider, integrate, and reason through mental representations, is central to our daily experience and has been suggested to serve crucial adaptive purposes. Such thinking occurs among other experiences during mind wandering that is associated with activation of the default mode network among other brain circuitries. Whether and how such brain activation is linked to the experience of spontaneous thinking per se remains poorly known. We studied 51 healthy subjects using a comprehensive experience-sampling paradigm during 3T functional magnetic resonance imaging. In comparison with fixation, the experiences of spontaneous thinking and spontaneous perception were related to activation of wide-spread brain circuitries, including the cortical midline structures, the anterior cingulate cortex and the visual cortex. In direct comparison of the spontaneous thinking versus spontaneous perception, activation was observed in the anterior dorsomedial prefrontal cortex. Modality congruence of spontaneous-experience-related brain activation was suggested by several findings, including association of the lingual gyrus with visual in comparison with non-verbal-non-visual thinking. In the context of current literature, these findings suggest that the cortical midline structures are involved in the integrative core substrate of spontaneous thinking that is coupled with other brain systems depending on the characteristics of thinking. Furthermore, involvement of the anterior dorsomedial prefrontal cortex suggests the control of high-order abstract functions to characterize spontaneous thinking per se. Hum Brain Mapp 38:3277-3288, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. [Spontaneous antepartal RhD alloimmunization].

    Science.gov (United States)

    Studničková, M; Holusková, I; Durdová, V; Kratochvílová, T; Strašilová, P; Marková, I; Lubušký, M

    2015-12-01

    Assess the incidence of spontaneous antepartal RhD alloimmunization in RhD negative pregnant women with an RhD positive fetus. Clinical study. Department of Obstetrics and Gynecology, Medical School and University Hospital Olomouc. A total of 906 RhD negative women with an RhD positive fetus and without the presence of anti-Dalloantibodies at the beginning of pregnancy were examined. Always it was a singleton pregnancy, RhD blood group of the pregnant women was assessed in the 1st trimester of pregnancy, RhD status of the fetus was determined after delivery. Screening for irregular antierythrocyte antibodies was performed in all women in the 1st trimester of pregnancy, at 28-32 weeks gestation and immediately prior to delivery at 38-42 weeks gestation. Screening for irregular antierythrocyte antibodies was performed also at 6 months following delivery in all cases of positive antibodies before delivery. Antibody screening was performed using the indirect antiglobulin (LISS/NAT) and enzyme (papain) test with their subsequent identification using a panel of reference erythrocytes by column agglutination method Dia-Med. After delivery, the volume of fetomaternal hemorrhage was assesed in all RhD negative women and RhD alloimmunization prophylaxis was performed by administering the necessary IgG anti-D dose; none of the women were administered IgG anti-D antepartally. During screening for irregular antierythrocyte antibodies at 28-32 weeks gestation, anti-D alloantibodies were diagnosed in 0.2% of the women (2/906); immediately prior to the delivery at 38-42 weeks gestation, anti-D alloantibodies were diagnosed in 2.3% of the women (21/906) and repeatedly even at 6 months following delivery (21/157). In 82.7% of the women (749/906), examination at 6 months following delivery was not performed, therefore in these women spontaneous antepartal RhD alloimmunization cannot reliably be ruled out. Alloimmunization may not be diagnosed yet at term of delivery. If anti

  12. Embebição de sementes de soja em solução de fosfato de potássio Soybean seeds imbibition in potassium phosphate solution

    Directory of Open Access Journals (Sweden)

    Claudia Antonia Vieira Rossetto

    2002-03-01

    quality. Drying the seeds accentuates the damages caused by the imbibition methodology.

  13. Traceability of biopharmaceuticals in spontaneous reporting systems

    DEFF Research Database (Denmark)

    Vermeer, Niels S; Straus, Sabine M J M; Mantel-Teeuwisse, Aukje K

    2013-01-01

    , including spontaneous reporting systems (SRSs), in which reports of ADRs are collected. OBJECTIVE: The aim of this study was to explore the current status of traceability of biopharmaceuticals in the US and the EU up to patient level in SRSs. DESIGN AND SETTING: A cross-sectional study was conducted over......BACKGROUND: Adverse drug reactions (ADRs) of biopharmaceuticals can be batch or product specific, resulting from small differences in the manufacturing process. Detailed exposure information should be readily available in systems for postmarketing safety surveillance of biopharmaceuticals...... the period 2004-2010, including ADR reports from two major SRSs: the FDA Adverse Event Reporting System (FAERS) in the US and EudraVigilance (EV) in the EU. MAIN OUTCOME MEASURES: The availability of batch numbers was determined for biopharmaceuticals, and compared with small molecule drugs...

  14. Spontaneously abandoned settlements in Serbia: Part 2

    Directory of Open Access Journals (Sweden)

    Milošević Marko V.

    2011-01-01

    Full Text Available This is the second part of the article “Spontaneously abandoned settlements in Serbia”, the first part of which was published in No. 60-2 of this Journal. Geomorphological indicators pointing at unsustainability of the studied settlements are singled out. The indicators are classified as morphometric (quantitative and morphologic (qualitative. Geomorphometry has been used for determination of quantitative indicators. The coefficient of settlement isolation (Ki is defined, which is a product of road coefficient (Kr and real relative height (RRH. Morphological indicators refer to the position of a settlement on a certain geomorphological unit (ridge, valley, valley side, as well as to the geomorphological homogeneity of space, determined by geomorphological mapping. The defined indicators of unsustainability are presented in detail as a case study of the abandoned village Smilov Laz, in the municipality of Novi Pazar.

  15. Spontaneous galactosylation of agalactoglycoproteins in colostrum.

    Science.gov (United States)

    Oubihi, M; Kitajima, K; Aoki, N; Matsuda, T

    2000-05-12

    We have found that spontaneous galactosylation of GlcNAc residues occurs in bovine colostrum, but not in dialyzed colostrum, without adding UDP-Gal as a donor substrate. UDP-Gal was shown to be present in bovine colostrum at a level ranging from 200 to 600 microM. When a tracer UDP-[(14)C]Gal was added to the dialyzed colostrum together with a Gal beta1,4-specific beta-galactosidase, remarkable incorporation of radioactivity into 24-28 kDa and 33 kDa RCA1-positive glycoproteins was demonstrated by SDS-PAGE/autoradiography. Some 100-140 kDa agalactoglycoproteins of a CHO mutant cell line were also galactosylated on a blotted membrane by the incubation in the colostrum.

  16. Pneumomediastin spontané chez un asthmatique

    Science.gov (United States)

    Elmoqaddem, Amine; Serghini, Issam; Janah, Hicham; Chouikh, Chakib; Alaoui, Amine; Bensghir, Mustapha

    2016-01-01

    Le pneumomédiastin spontané est une pathologie rare. Il se voit surtout chez l’adulte jeune. Sa survenue brutale est caractéristique, associant une douleur thoracique, un emphysème sous-cutané et une dyspnée. Nous rapportons l’observation d’un pneumomédiastin, chez un patient de 24 ans asthmatique déclenché suite à un effort de toux. Le patient s’est présenté dans un tableau d’insuffisance respiratoire aigue avec une douleur thoracique retrosternale. La radiographie pulmonaire a confirmé le diagnostic de pneumomédiastin. L’évolution a été favorable en 4 jours après exsufflation, oxygénothérapie et traitement médical conventionnel. PMID:28292057

  17. Constrained Gauge Fields from Spontaneous Lorentz Violation

    CERN Document Server

    Chkareuli, J L; Jejelava, J G; Nielsen, H B

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type $A_{\\mu}^{2}=M^{2}$ ($M$ is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory proves to be QED with a massless vector Goldstone boson naturally associated with the photon, while the non-Abelian symmetry case results in a conventional Yang-Mills theory. These theories, both Abelian and non-Abelian, look essentially nonlinear and contain particular Lorentz (and $CPT$) violating couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical ...

  18. Spontaneous unilamellar polymer vesicles in aqueous solution.

    Science.gov (United States)

    Kim, Tae-Hwan; Song, Chaeyeon; Han, Young-Soo; Jang, Jong-Dae; Choi, Myung Chul

    2014-01-21

    A unilamellar polymeric vesicle is a self-assembled structure of a block copolymer that forms a spherical single bilayer structure with a hydrophobic interlayer and a hydrophilic surface. Due to their enhanced colloidal stability and mechanical property, controllable surface functionality, or tunable membrane thickness, polymeric vesicles are useful in nano and bio-science, providing potential applications as nanosized carriers for catalysts, drugs, and enzymes. For fabrication of a unilamellar vesicle, however, preparative procedures with a few steps are inherently required. Herein, without complicated preparative procedures, we report spontaneous unilamellar polymeric vesicles with nanometer sizes (small angle neutron scattering and cryo-TEM, resulting in a phase diagram drawn as a function of temperature and the 5mS concentration. Interestingly the critical temperature for the micelle-to-vesicle phase transition was easily controlled by varying the 5mS concentration, i.e. it was decreased with increasing the 5mS concentration.

  19. Spontaneous jamming in one-dimensional systems

    Science.gov (United States)

    O'Loan, O. J.; Evans, M. R.; Cates, M. E.

    1998-04-01

    We study the phenomenon of jamming in driven diffusive systems. We introduce a simple microscopic model in which jamming of a conserved driven species is mediated by the presence of a non-conserved quantity, causing an effective long-range interaction of the driven species. We study the model analytically and numerically, providing strong evidence that jamming occurs; however, this proceeds via a strict phase transition (with spontaneous symmetry breaking) only in a prescribed limit. Outside this limit, the nearby transition (characterised by an essential singularity) induces sharp crossovers and transient coarsening phenomena. We discuss the relevance of the model to two physical situations: the clustering of buses, and the clogging of a suspension forced along a pipe.

  20. Spontaneous aortic dissecting hematoma in two dogs.

    Science.gov (United States)

    Boulineau, Theresa Marie; Andrews-Jones, Lydia; Van Alstine, William

    2005-09-01

    This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation.

  1. A Young Man with Bilateral Spontaneous Pneumothorax

    Directory of Open Access Journals (Sweden)

    Liese Lieve Willemien Verhaert

    2011-01-01

    Full Text Available Case. A 33-year-old male nonsmoker presented with sudden onset of dyspnoea and thoracic pain. Chest radiograph showed a left-sided pneumothorax. Few days later he developed a right-sided pneumothorax. He had a positive family history of pneumothorax. High-resolution computed tomography of the chest showed multiple pulmonary cysts predominantly located in the lower lung regions. We suspected Birt-Hogg-Dubé syndrome (BHD. Conclusion. Birt-Hogg-Dubé syndrome is a rare autosomal dominant inherited genodermatosis and characterised by clinical manifestations including hamartomas of the skin, renal tumors, and pulmonary cysts with spontaneous pneumothorax. BHD is probably underdiagnosed because of the wide variability in its clinical expression. It is important to recognize these patients because of the possibility of developing renal cancer.

  2. Constrained gauge fields from spontaneous Lorentz violation

    DEFF Research Database (Denmark)

    Chkareuli, J. L.; Froggatt, C. D.; Jejelava, J. G.

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type AµAµ=M2 (M is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant...... theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory...... couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical Lorentz violation due to the simultaneously generated gauge invariance. Udgivelsesdato: June 11...

  3. Spontaneous Esophageal Injury: Esophageal Intramural Hematoma

    Directory of Open Access Journals (Sweden)

    Yu-Hui Chiu

    2009-09-01

    Full Text Available Acute chest pain can indicate a life-threatening condition and it is important for physicians to diagnose and treat it as a matter of urgency. We report 1 rare case of esophageal intramural hematoma (IMH that presented with chest pain at the emergency department and which was initially clinically suspected to be due to aortic dissection. The case was diagnosed preoperatively by multidetector computed tomography. Esophageal IMH may represent an intermediate stage between Mallory-Weiss tear (mucosal and Boerhaave's syndrome (transmural. Multidetector computed tomography is a useful noninvasive imaging modality for accurate diagnosis of these spontaneous intramural and transmural ruptures of the esophagus, and aids in the differential diagnosis of aortic and other mediastinal diseases with acute chest pain.

  4. Spontaneous spherical symmetry breaking in atomic confinement

    Science.gov (United States)

    Sveshnikov, Konstantin; Tolokonnikov, Andrey

    2017-07-01

    The effect of spontaneous breaking of initial SO(3) symmetry is shown to be possible for an H-like atom in the ground state, when it is confined in a spherical box under general boundary conditions of "not going out" through the box surface (i.e. third kind or Robin's ones), for a wide range of physically reasonable values of system parameters. The most novel and nontrivial result, which has not been reported previously, is that such an effect takes place not only for attractive, but also for repulsive interactions of atomic electrons with the cavity environment. Moreover, in the limit of a large box size R ≫ aB the regime of an atom, soaring over a plane with boundary condition of "not going out", is reproduced, rather than a spherically symmetric configuration, which would be expected on the basis of the initial SO(3) symmetry of the problem.

  5. Spontaneous Heterotopic Triplet Pregnancy With Tubal Rupture

    Directory of Open Access Journals (Sweden)

    Lima Arsala MBBS, BBMedSci

    2014-04-01

    Full Text Available The recent increase in heterotopic pregnancies has been largely attributed to the increased use of assisted reproduction technologies. We report the rare case of a multiparous woman with a spontaneous conception resulting in a triplet heterotopic pregnancy: a twin intrauterine pregnancy and a single right tubal ectopic pregnancy. Heterotopic pregnancy is a rare and potentially life-threatening condition in which simultaneous gestations occur at 2 or more implantation sites. It is infrequent in natural conception cycles, occurring in 1:30 000 pregnancies. However, the prevalence is rising with the increased use of assisted reproduction techniques to that of 1:100 to 1:500 in these patient subgroups, highlighting the need to incorporate it into a clinician’s diagnostic algorithm.

  6. Radionuclide evaluation of spontaneous femoral osteonecrosis

    International Nuclear Information System (INIS)

    Greyson, N.D.; Lotem, M.M.; Gross, A.E.; Houpt, J.B.

    1982-01-01

    Spontaneous osteonecrosis of the femoral condyle in 40 knees was followed by sequential radiographs and three-phase bone scans using 99 /sup m/Tc-methylene diphosphonate. The characteristic bone scan appearance of focal increased uptake by the medial femoral condyle in blood flow, blood pool, and delayed images helped to make the specific diagnosis in 11 knees that had no characteristic radiographic findings at the time of presentation. The three phases of the bone scan demonstrated a pattern that was useful in determining the activity of the process. There was a gradual loss of hyperemia as healing progressed. Late bone scans were normal or showed nonspecific findings. Radionuclide bone scans were able to confirm or exclude this disease and were superior to radiographs in demonstrating the disease in the acute phase

  7. Spontaneous closure of midline diastema following frenectomy

    Directory of Open Access Journals (Sweden)

    Koora Kiran

    2007-03-01

    Full Text Available Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

  8. Glioblastoma Multiforme Presenting as Spontaneous Intracerebral Hemorrhage

    Directory of Open Access Journals (Sweden)

    Cagatay Ozdol

    2014-06-01

    Full Text Available Brain tumors with concomitant intracerebral hemorrhage are rarely encountered. Hemorrhage as the initial presentation of a brain tumour may pose some diagnostic problems, especially if the tumour is small or the hemorrhage is abundant. We present a 47-year-old man who admitted to the emergency department with sudden onset headache, right blurred vision and gait disturbance. A non-contrast cranial computerized tomography scan performed immediately after his admission revealed a well circumscribed right occipitoparietal haematoma with intense peripheral edema causing compression of the ipsilateral ventricles. On 6th hour of his admission the patient%u2019s neurological status deteriorated and he subsequently underwent emergent craniotomy and microsurgical evacuation of the haematoma. The histopathological examination of the mass was consistent with a glioblastoma multiforme. Neoplasms may be hidden behind each case of spontaneous intracerebral hemorrhage. Histological sampling and investigation is mandatory in the presence of preoperative radiological features suggesting a neoplasm.

  9. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, O. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D. [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  10. Dissipative Continuous Spontaneous Localization (CSL) model.

    Science.gov (United States)

    Smirne, Andrea; Bassi, Angelo

    2015-08-05

    Collapse models explain the absence of quantum superpositions at the macroscopic scale, while giving practically the same predictions as quantum mechanics for microscopic systems. The Continuous Spontaneous Localization (CSL) model is the most refined and studied among collapse models. A well-known problem of this model, and of similar ones, is the steady and unlimited increase of the energy induced by the collapse noise. Here we present the dissipative version of the CSL model, which guarantees a finite energy during the entire system's evolution, thus making a crucial step toward a realistic energy-conserving collapse model. This is achieved by introducing a non-linear stochastic modification of the Schrödinger equation, which represents the action of a dissipative finite-temperature collapse noise. The possibility to introduce dissipation within collapse models in a consistent way will have relevant impact on the experimental investigations of the CSL model, and therefore also on the testability of the quantum superposition principle.

  11. Dynamic Oil-Water and Air-Water Capillary Pressure-Saturation Curves: Experiments and Lattice-Boltzmann Simulations

    Science.gov (United States)

    Porter, M. L.; Schaap, M. G.; Wildenschild, D.

    2006-12-01

    Capillary pressure plays a significant role in multiphase flow and transport in porous media. Although capillary forces occur at the pore-scale, many mathematical models require a macro-scale relationship between capillary pressure and other properties of the system. The capillary pressure-saturation curve is the most widely used relationship to characterize hydraulic properties of multiphase flow in porous media. These curves are most commonly obtained from quasi-static drainage and imbibition experiments. It is then often assumed that the quasi-static curves can be applied to modeling transient flow conditions. In these models, the time it takes to reach a quasi-static state is completely ignored, which can be on the order of hours to months. Experimental evidence suggests that capillary pressure-saturation curves are not unique and that they exhibit dynamic effects depending on the flow conditions in the the system prior to and during the time of measurement. The extent to which dynamic flow conditions effect the measured capillary pressure is currently debated and the exact cause of the observed dynamic effects is not fully understood. In this study various drainage and imbibition experiments were conducted to further investigate the role dynamic effects play in the capillary pressure-saturation curve. Oil-water and air-water experiments were conducted on the same porous medium to compare the dynamic effects resulting from density and viscosity differences. Lattice-Boltzmann simulations of the dynamic effects were carried out to provide a comparison to the experimental results. The simulation results were then analyzed in an effort to identify the pore-scale mechanisms responsible for the dynamic effects observed in the macro-scale experiments.

  12. Spontaneous activity in peripheral diaphragmatic lymphatic loops.

    Science.gov (United States)

    Moriondo, Andrea; Solari, Eleonora; Marcozzi, Cristiana; Negrini, Daniela

    2013-10-01

    The spontaneous contractility of FITC-dextran-filled lymphatics at the periphery of the pleural diaphragm was documented for the first time "in vivo" in anesthetized Wistar rats. We found that lymphatic segments could be divided into four phenotypes: 1) active, displaying rhythmic spontaneous contractions (51.8% of 197 analyzed sites); 2) stretch-activated, whose contraction was triggered by passive distension of the vessel lumen (4.1%); 3) passive, which displayed a completely passive distension (4.5%); and 4) inert, whose diameter never changed over time (39.6%). Smooth muscle actin was detected by immunofluorescence and confocal microscopy in the vessel walls of active but also of inert sites, albeit with a very different structure within the vessel wall. Indeed, while in active segments, actin was arranged in a dense mesh completely surrounding the lumen, in inert segments actin decorated the vessels wall in sparse longitudinal strips. When located nearby along the same lymphatic loop, active, stretch-activated, and passive sites were always recruited in temporal sequence starting from the active contraction. The time delay was ∼0.35 s between active and stretch-activated and 0.54 s between stretch-activated and passive segments, promoting a uniform lymph flux of ∼150/200 pl/min. We conclude that, unlike more central diaphragmatic lymphatic vessels, loops located at the extreme diaphragmatic periphery do require an intrinsic pumping mechanism to propel lymph centripetally, and that such an active lymph propulsion is attained by means of a complex interplay among sites whose properties differ but are indeed able to organize lymph flux in an ordered fashion.

  13. Risk factors for recurrent spontaneous epistaxis.

    Science.gov (United States)

    Abrich, Victor; Brozek, Annabelle; Boyle, Timothy R; Chyou, Po-Huang; Yale, Steven H

    2014-12-01

    To identify risk factors associated with spontaneous recurrent epistaxis. This was a retrospective cohort study assessing patients in the Marshfield Clinic system diagnosed as having epistaxis between January 1, 1991, and January 1, 2011. There were 461 cases with at least 2 episodes of spontaneous epistaxis within 3 years and 912 controls with only 1 episode in the same time frame. More than 50 potential risk factors were investigated, including demographic features, substance use, nasal anatomical abnormalities, nasal infectious and inflammatory processes, medical comorbidities, medications, and laboratory values. A Cox proportional hazards regression modeling approach was used to calculate hazard ratios of epistaxis recurrence. Traditional risk factors for epistaxis, including nasal perforation, nasal septum deviation, rhinitis, sinusitis, and upper respiratory tract infection, did not increase the risk of recurrence. Significant risk factors for recurrent epistaxis included congestive heart failure, diabetes mellitus, hypertension, and a history of anemia. Warfarin use increased the risk of recurrence, independent of international normalized ratio. Aspirin and clopidogrel were not found to increase the risk of recurrence. Few major adverse cardiovascular events were observed within 30 days of the first epistaxis event. Congestive heart failure is an underappreciated risk factor for recurrent epistaxis. Hypertension and diabetes mellitus may induce atherosclerotic changes in the nasal vessels, making them friable and more at risk for bleeding. Patients with recurrent epistaxis may also be more susceptible to developing anemia. Physicians should promote antiplatelet and antithrombotic medication adherence despite an increased propensity for recurrent epistaxis to prevent major adverse cardiovascular events. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  14. Spontaneous trait inference and spontaneous trait transference are both unaffected by prior evaluations of informants.

    Science.gov (United States)

    Zengel, Bettina; Ambler, James K; McCarthy, Randy J; Skowronski, John J

    2017-01-01

    This article reports results from a study in which participants encountered either (a) previously known informants who were positive (e.g. Abraham Lincoln), neutral (e.g., Jay Leno), or negative (e.g., Adolf Hitler), or (b) previously unknown informants. The informants ostensibly described either a trait-implicative positive behavior, a trait-implicative negative behavior, or a neutral behavior. These descriptions were framed as either the behavior of the informant or the behavior of another person. Results yielded evidence of informant-trait linkages for both self-informants and for informants who described another person. These effects were not moderated by informant type, behavior valence, or the congruency or incongruency between the prior knowledge of the informant and the behavior valence. Results are discussed in terms of theories of Spontaneous Trait Inference and Spontaneous Trait Transference.

  15. Spontaneous breakdown of PT symmetry in the complex Coulomb ...

    Indian Academy of Sciences (India)

    Keywords. Spontaneous breakdown of PT symmetry; Coulomb potential; complex en- ergy eigenvalues. PACS Nos 03.65.Ge; 03.65.Nk; 11.30.Er. 1. Introduction. One of the most intriguing features of PT -symmetric quantum mechanics is the spontaneous breakdown of PT symmetry. This phenomenon was noted in the first.

  16. Safety of Oral Clemastine – Analysis of Data from Spontaneous ...

    African Journals Online (AJOL)

    event reporting system. Methods: We analyzed sales volume and data obtained from the monitoring of spontaneous reports on ... existing spontaneous monitoring system for adverse effects in Poland may not be sensitive enough and therefore, needs improvement. ... which is based on current EU legislation. As part.

  17. Spontaneous splenic rupture in pregnancy: a case report | Makwe ...

    African Journals Online (AJOL)

    Spontaneous splenic rupture in pregnancy is a rare condition, associated with very high maternal mortality rate and fetal wastage. It is frequently misdiagnosed at presentation. We report a case of a 33-year-old, gravida 2, para 1 lady at 29 weeks' gestation with spontaneous splenic rupture, which was initially diagnosed as ...

  18. Spontaneous massive vulva swelling in pregnancy: a case report ...

    African Journals Online (AJOL)

    Spontaneous massive vulva edema is not common during pregnancy, but its presence possesses management challenges with significant patient anxiety and discomfort. We report a case of spontaneous vulva edema in a 24-year old primigravida at 28 weeks gestational age havingtwin gestation, with one anaecephalyand ...

  19. Safety of Oral Clemastine – Analysis of Data from Spontaneous ...

    African Journals Online (AJOL)

    Purpose: To analyse the safety of oral clemastine marketed in Poland based on spontaneous adverse event reporting system. Methods: We analyzed sales volume and data obtained from the monitoring of spontaneous reports on the adverse effects of Clemastinum Hasco tablets (1.0 mg) and Clemastinum Hasco syrup (0.1 ...

  20. Spontaneous vortex phase (SVP) of ruthenocuprate high Tc ...

    Indian Academy of Sciences (India)

    RuSr2(RE1.5Ce0.5)Cu2O10, has given rise to the concept of spontaneous vortex phase (SVP). In these compounds, the magnetic ordering temperature (Tmag >. 100 K) is higher than the superconducting transition temperature (Tc ~ 30 K). Hence, due to internal magnetic fields, these compounds remain in a spontaneous.

  1. Spontaneous infected biloma: case report | Kimani | East African ...

    African Journals Online (AJOL)

    Biloma is defined as any collection of bile outside the biliary tree. It mainly results from surgical complications and abdominal trauma. Spontaneous biloma is extremely rare and is occasionally associated with choledocholithiasis. This report describes a case of spontaneous biloma diagnosed radiologically and confirmed at ...

  2. Spontaneous rupture: An uncommon complication of ventral hernia ...

    African Journals Online (AJOL)

    BACKGROUND: Literature is scarce about spontaneous rupture of hernia because spontaneous rupture of here is uncommon (1). Reported cases are complications of incisional hernias, recurrent inguinal hernia, and umbilical hernias. It is potentially life threatening (1) because the ensuing entrapment and tension on ...

  3. A comparison of spontaneous combustion susceptibility of coal from ...

    African Journals Online (AJOL)

    This study investigated spontaneous combustion susceptibility of coal according to the rank. To estimate the spontaneous combustion susceptibility of coal, both crossing-point temperature (CPT) measurement and gas analysis by using gas chromatography (GC) were performed. For the experiment, Ihuoma coal, Orlu ...

  4. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases; thi...

  5. Role of ascitic fluid C3 in spontaneous bacterial peritonitis

    African Journals Online (AJOL)

    Amany Talaat Kamal

    2012-02-29

    Feb 29, 2012 ... [13] Terg R, Fassio E, Guevara M. Ciprofloxacin in primary prophy- laxis of spontaneous bacterial peritonitis: a randomized, placebo controlled study. J Hepatol 2008;48(5):774–9. [14] Akriviadis EA, Runyon BA. Utility of an algorithm in differen- tiating spontaneous from secondary bacterial peritonitis. Gastro ...

  6. Spontaneous magnetization in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constanca

    2015-01-01

    It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous...

  7. Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

    DEFF Research Database (Denmark)

    Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin

    2016-01-01

    by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point...

  8. Spontaneous herniation of the thoracic spinal cord : a case report

    International Nuclear Information System (INIS)

    Jin, Sung Chan; Lee, Seong Ro; Park, Dong Woo; Joo, Kyung Bin

    2001-01-01

    Spontaneous herniation of the spinal cord is a rare disease entity in which spinal cord substance is herniated through a previously uninjured and/or untouched dural. It is a cause of myelopathy that is treatable but difficult to diagnose. We report the CT and MR findings of a case of spontaneous thoracic spinal cord through a dural defect

  9. Spontaneous perforation by pyometra — an acute emergency ...

    African Journals Online (AJOL)

    Spontaneous perforation by pyometra — an acute emergency. B Gupta, R Agarwal, G Radhakrishnan. Abstract. Accumulation of pus in the uterine cavity is termed pyometra and has an incidence of 0.1 - 0.5%.1 We report a case of spontaneous pyometra rupture with subsequent peritonitis. Full Text: EMAIL FREE FULL ...

  10. A Rare Case of Peritonitis Following Spontaneous Rupture of ...

    African Journals Online (AJOL)

    Chan LY, Yu VS, HO LC, Lok YH, Hui SK. Spontaneous uterine perforation of pyometra. A report of three cases. J Reprod Med 2000;45:857-60. 5. Bostofte E, Legarth J. Spontaneous perforation of pyometra with diffuse peritonitis. Acta Obstet Gynecol Scand 1981;60:511-2. 6. Nakao A, Mimura H, Fujisawa K. Generalized ...

  11. Computed Tomography Features of Spontaneously Perforated Pyometra: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.S.; Tan, C.K.; Mak, C.W.; Chia, C.C.; Kuo, C.Y.; Yu, W.L. [Chi-Mei Medical Center, Tainan, Taiwan (China). Depts. of Intensive Care Medicine, Radiology, Obstetrics and Gynecology, and Surgery

    2006-03-15

    Spontaneous perforation of pyometra is an extremely rare emergent gynecologic disease. We report a 73-year-old woman with a spontaneously perforated pyometra presenting with acute abdomen in the emergency department. A dedicated computed tomography examination of the abdominal and pelvic regions revealed the diagnosis. The patient recovered well after surgical intervention and antibiotic treatment.

  12. Spontaneous resolution of post-traumatic chronic subdural hematoma

    African Journals Online (AJOL)

    Here, we present a case of spontaneously resolved post-traumatic bilateral chronic subdural hematoma within a period of one month in a 55-year-old male and we discuss the probable mechanisms of pathophysiology in the spontaneous resolution of chronic subdural hematoma. Keywords: Antiaggregation therapy, chronic ...

  13. Spontaneity and Equilibrium III: A History of Misinformation

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    Necessary and sufficient criteria for reaction spontaneity in a given direction and for spontaneity of finite transformations in single-reaction, closed systems are developed. The criteria are general in that they hold for reactions conducted under either conditions of constant T and p or constant T and V. These results are illustrated using a…

  14. Bilateral spontaneous rupture of flexor digitorum profundus tendons.

    LENUS (Irish Health Repository)

    O'Sullivan, S T

    2012-02-03

    Spontaneous tendon rupture is an unusual condition usually associated with underlying disease processes such as rheumatoid arthritis, chronic renal failure or bony abnormalities of the hand. We report a case of spontaneous, non-concurrent bilateral rupture of flexor profundus tendons in an otherwise healthy individual. Treatment was successful and consisted of a two-stage reconstruction of the ruptured tendon.

  15. Q-feber som årsag til spontan abort

    DEFF Research Database (Denmark)

    Nielsen, Stine Yde; Mølbak, Kåre; Hjøllund, Niels Henrik

    2011-01-01

    Q-fever is a zoonotic infection. Pregnant women constitute a specific risk group as the infection may cause spontaneous abortion, intrauterine death, growth retardation, oligohydramnios and premature birth. A 39 year-old veterinarian had a spontaneous abortion in pregnancy week seven. During...

  16. Spontaneous poisoning by Prosopis juliflora (Leguminosae) in sheep

    Science.gov (United States)

    The aim of this paper is to describe the first report of clinical, epidemiological and pathological aspects of spontaneous poisoning by Prosopis juliflora in sheep. Of a total of 500 sheep at risk, two adult male sheep were affected; one died spontaneously and the other animal was examined, euthaniz...

  17. Two Cases of Subdural Hematoma in Spontaneous CSF Hypovolemia

    OpenAIRE

    島谷, 佳光; 井戸川, 美帆; 阿部, 剛典; 仁平, 敦子; 溝渕, 雅広; 佐光, 一也; 田中, 千春

    2007-01-01

    Two cases of subdural hematoma in spontaneous CSF hypovolemia. The typical orthostatic features were replaced by continuous, nonpositional headache. MEI showed subdural hematoma. These cases emphasize that spontaneous CSF hypovolemia is not an entirely benign condition and that subudural hematoma may accompany persistent intracranial hypotension.

  18. Spontaneous Uterine Rupture during Pregnancy: Case Report and ...

    African Journals Online (AJOL)

    Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient. The case was managed at the University Teaching Hospital of Yaounde (Cameroon). She had past history of ...

  19. Spontaneous Activity Drives Local Synaptic Plasticity In Vivo

    NARCIS (Netherlands)

    Winnubst, Johan; Cheyne, Juliette E; Niculescu, Dragos; Lohmann, C.

    2015-01-01

    Spontaneous activity fine-tunes neuronal connections in the developing brain. To explore the underlying synaptic plasticity mechanisms, we monitored naturally occurring changes in spontaneous activity at individual synapses with whole-cell patch-clamp recordings and simultaneous calcium imaging in

  20. A Neonatal Pneumonia Presented with Spontaneous Pneumothorax Due to Listeria Monositogenes

    Directory of Open Access Journals (Sweden)

    Mehmet Karaci

    2016-01-01

    Full Text Available Listeria Monositogenes is a facultative anaerob gram(+ agents that presents in soil, water, plants and in many mammals intestinal system.  Listeria Monositogenes is one of the most common factors of early neonatal sepsis and neonatal pneumonia during the perinatal period. Maternal obstetric complications are frequently seen in patients. Patients are often premature and have low birth weight. Responsible microorganisms frequently originate from maternal. The disease involes multisystems and the prognosis is usually fulminant.  In the congenital pneumonia, respiratory distress syndrome is prominent. Symptomatic spontaneous pneumothorax  brings about serious morbidity and mortality in newborns. The cause and risk factors of symptomatic pneumothorax in term newborns are not completely understood. The risk factors were reported as prematurity, male sex, high birth weight and birth the use of vacuum. We aimed to present a case with neonatal pneumonia associated with symptomatic spontaneous pneumothorax due to Listeria Monositogenes.

  1. Spontaneous generation in medieval Jewish philosophy and theology.

    Science.gov (United States)

    Gaziel, Ahuva

    2012-01-01

    The concept of life forms emerging from inanimate matter--spontaneous generation--was widely accepted until the nineteenth century. Several medieval Jewish scholars acknowledged this scientific theory in their philosophical and religious contemplations. Quite interestingly, it served to reinforce diverse, or even opposite, theological conclusions. One approach excluded spontaneously-generated living beings form the biblical account of creation or the story of the Deluge. Underlying this view is an understanding that organisms that generate spontaneously evolve continuously in nature and, therefore, do not require divine intervention in their formation or survival during disastrous events. This naturalistic position reduces the miraculous dimension of reality. Others were of the opinion that spontaneous generation is one of the extraordinary marvels exhibited in this world and, accordingly, this interpretation served to accentuate the divine aspect of nature. References to spontaneous generation also appear in legal writings, influencing practical applications such as dietary laws and actions forbidden on the Sabbath.

  2. The effects of age and divided attention on spontaneous recognition.

    Science.gov (United States)

    Anderson, Benjamin A; Jacoby, Larry L; Thomas, Ruthann C; Balota, David A

    2011-05-01

    Studies of recognition typically involve tests in which the participant's memory for a stimulus is directly questioned. There are occasions however, in which memory occurs more spontaneously (e.g., an acquaintance seeming familiar out of context). Spontaneous recognition was investigated in a novel paradigm involving study of pictures and words followed by recognition judgments on stimuli with an old or new word superimposed over an old or new picture. Participants were instructed to make their recognition decision on either the picture or word and to ignore the distracting stimulus. Spontaneous recognition was measured as the influence of old vs. new distracters on target recognition. Across two experiments, older adults and younger adults placed under divided-attention showed a greater tendency to spontaneously recognize old distracters as compared to full-attention younger adults. The occurrence of spontaneous recognition is discussed in relation to ability to constrain retrieval to goal-relevant information.

  3. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases......; this report is the first to document complete spontaneous regression of cerebral metastases from malignant melanoma by means of computed tomography scans. Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour in the absence of all treatment or in the presence...... of therapy, which is considered inadequate to exert a significant influence on neoplastic disease. The incidence of spontaneous regression of metastases from malignant melanoma is approximately one per 400 patients, and possible mechanisms include immunologic, endocrine, inflammatory and tumour nutritional...

  4. Spontaneous mutation rates and the rate-doubling dose

    International Nuclear Information System (INIS)

    Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

    1978-01-01

    The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

  5. Spontaneous formation of gold nanostructures in aqueous microdroplets.

    Science.gov (United States)

    Lee, Jae Kyoo; Samanta, Devleena; Nam, Hong Gil; Zare, Richard N

    2018-04-19

    The synthesis of gold nanostructures has received widespread attention owing to many important applications. We report the accelerated synthesis of gold nanoparticles (AuNPs), as well as the reducing-agent-free and template-free synthesis of gold nanoparticles and nanowires in aerosol microdroplets. At first, the AuNP synthesis are carried out by fusing two aqueous microdroplet streams containing chloroauric acid and sodium borohydride. The AuNPs (~7 nm in diameter) are produced within 60 µs at the rate of 0.24 nm µs -1 . Compared to bulk solution, microdroplets enhance the size and the growth rate of AuNPs by factors of about 2.1 and 1.2 × 10 5 , respectively. Later, we find that gold nanoparticles and nanowires (~7 nm wide and >2000 nm long) are also formed in microdroplets in the absence of any added reducing agent, template, or externally applied charge. Thus, water microdroplets not only accelerate the synthesis of AuNPs by orders of magnitude, but they also cause spontaneous formation of gold nanostructures.

  6. Modelling spontaneous combustion in wet lignite

    Science.gov (United States)

    Gong, Rose; Burnell, John G.; Wake, Graeme C.

    1999-06-01

    A model of self-heating of wet coal is presented. This involves coupled heat and mass transport within a coal pile, together with an exothermic reaction and phase changes of water. There are four state variables: temperature, oxygen, water vapour and liquid water concentrations. Heat and mass are conducted or diffused through the pile, while simultaneously undergoing chemical reaction. As demonstrated by experiment, the heat release rate depends in a quadratic fashion on the liquid water content and this feature is a distinctive aspect of the model. After development of the model, an illustrative spatially uniform model of just three state variables (temperature, oxygen and liquid water concentrations) is analysed for its bifurcational structure of steady states, periodic solutions and their stability. By this means, thresholds for the onset of ignition can be determined as a function of the physical and chemical parameters.

  7. Unbiased Spontaneous Solar Fuel Production using Stable LaFeO3 Photoelectrode.

    Science.gov (United States)

    Pawar, Govinder S; Tahir, Asif A

    2018-02-22

    Photoelectrochemical (PEC) water splitting to produce solar fuel (hydrogen) has long been considered as the Holy Grail to a carbon-free hydrogen economy. The PEC concept to produce solar fuel is to emulate the natural photosynthesis using man made materials. The bottle-neck in realising the concept practically has been the difficulty in identifying stable low-cost semiconductors that meet the thermodynamic and kinetic criteria for photoelectrolysis. We have fabricated a novel p-type LaFeO 3 photoelectrode using an inexpensive and scalable spray pyrolysis method. Our nanostructured LaFeO 3 photoelectrode results in spontaneous hydrogen evolution from water without any external bias applied. Moreover, the photoelectrode has a faradaic efficiency of 30% and showed excellent stability over 21 hours. From optical and impedance data, the constructed band diagram showed that LaFeO 3 can straddle the water redox potential with the conduction band at -1.11 V above the reduction potential of hydrogen. We have fabricated a low cost LaFeO 3 photoelectrode that can spontaneously produce hydrogen from water using sunlight, making it a strong future candidate for renewable hydrogen generation.

  8. Spontaneous breakdown and the scalar nonet

    Energy Technology Data Exchange (ETDEWEB)

    Scadron, M.D.

    1982-07-01

    In the context of the QCD quark model and on the basis of dynamical Bethe-Salpeter ladder graphs, we suggest that (i) the existence of the scalar q-barq hadron multiplet, like the pseudoscalar q-barq multiplet, is a direct consequence of dynamical spontaneous breakdown of chiral symmetry with a chiral-limiting nonstrange mass scale of m/sub sigmaNS//sup CL/ = 2m/sub dyn/ roughly-equal630 MeV, (ii) the lifting of the nonstrange sigma-delta degeneracy is expected from the s-wave quark-gluon annihilation diagram, and (iii) the observed sigma-S* mixing follows from the existence of the p-wave scalar quark-annihilation diagram. The resulting predicted 0q-barq nonet is then sigma(750 MeV), kappa(800), S*(980), and delta(985), in agreement with data for the resonant masses, the mixing angle, and also decay widths except for the kappa(800).

  9. Enhancement of Pleasure during Spontaneous Dance

    Directory of Open Access Journals (Sweden)

    Nicolò F. Bernardi

    2017-11-01

    Full Text Available Dancing emphasizes the motor expression of emotional experiences. The bodily expression of emotions can modulate the subjective experience of emotions, as when adopting emotion-specific postures and faces. Thus, dancing potentially offers a ground for emotional coping through emotional enhancement and regulation. Here we investigated the emotional responses to music in individuals without any prior dance training while they either freely danced or refrained from movement. Participants were also tested while imitating their own dance movements but in the absence of music as a control condition. Emotional ratings and cardio-respiratory measures were collected following each condition. Dance movements were recorded using motion capture. We found that emotional valence was increased specifically during spontaneous dance of groovy excerpts, compared to both still listening and motor imitation. Furthermore, parasympathetic-related heart rate variability (HRV increased during dance compared to motor imitation. Nevertheless, subjective and physiological arousal increased during movement production, regardless of whether participants were dancing or imitating. Significant correlations were found between inter-individual differences in the emotions experienced during dance and whole-body acceleration profiles. The combination of movement and music during dance results in a distinct state characterized by acutely heightened pleasure, which is of potential interest for the use of dance in therapeutic settings.

  10. Sync the emerging science of spontaneous order

    CERN Document Server

    Strogatz, Steven

    2003-01-01

    At the heart of the universe is a steady, insistent beat, the sound of cycles in sync. Along the tidal rivers of Malaysia, thousands of fireflies congregate and flash in unison; the moon spins in perfect resonance with its orbit around the earth; our hearts depend on the synchronous firing of ten thousand pacemaker cells. While the forces that synchronize the flashing of fireflies may seem to have nothing to do with our heart cells, there is in fact a deep connection. Synchrony is a science in its infancy, and Strogatz is a pioneer in this new frontier in which mathematicians and physicists attempt to pinpoint just how spontaneous order emerges from chaos. From underground caves in Texas where a French scientist spent six months alone tracking his sleep-wake cycle, to the home of a Dutch physicist who in 1665 discovered two of his pendulum clocks swinging in perfect time, this fascinating book spans disciplines, continents, and centuries. Engagingly written for readers of books such as Chaos and The Elegant ...

  11. GdNCT of spontaneous canine melanoma

    International Nuclear Information System (INIS)

    Mitin, V.N.; Kulakov, V.N.; Khokhlov, V.F.

    2006-01-01

    The effectiveness of GdNCT has been studied in dogs with spontaneous melanoma of the mucousmembrane of the oral cavity patients on the NCT base at the IRT MEPhI reactor. The control group with melanomas was treated with neutrons. Fourteen canine patients were selected in the Clinic of Experimental Therapy affiliated with the RCRC RAMS. The calculation of doses has shown that the total dose of energy release depending on Gd concentration in the target can be several times higher than the dose produced by the reactor neutron beam. The calculations were carried out using the diffusion pharmacokinetic model. The gadolinium drug dipentast was administered intratumorally immediately prior to irradiation. The tumor size was estimated by measuring it in three projections. The tumor was irradiated for 60-90 minutes with a thermal neutron flux of 0.7x10 9 n/cm 2 s. The dose on tumor was 80-120 Gy, on surrounding tissues - 12-15 Gy. The treatment plan included immunotherapy with Roncoleikin in a dose of (15-10)x10 3 IE/kg. The results of GdNCT are still under observation. The results conform to those obtained by us earlier in cell cultures and inoculated experimental tumors. GdNCT is also effective in combination with immunotherapy. (author)

  12. Spontaneously settled refugees in Northwestern Province, Zambia.

    Science.gov (United States)

    Freund, P J; Kalumba, K

    1986-01-01

    The UN High Commissioner for Refugees (UNHCR) commissioned researchers from the University of Zambia to conduct a socioeconomic survey and census of "spontaneously settled" Zairean and Angolan refugees in the Northwestern Province of Zambia in 1982. The sample consisted of 188 Angolans, 201 Zaireans, and 2 South Africans. The difficulties experienced by refugees in Northwestern Province in achieving integration were related to a combination of factors including the lack of a clear national policy on refugees and refugee status, a national concern for maintaining security, the popular belief that aliens are responsible for an increasing crime rate, the desire by immigration officials for stricter laws to control alien infiltration, conflict between traditional and modern leaders, and Zambia's deteriorating economic situation. In spite of the problems described, the integration of refugees into existing communities is a desirable goal and should be encouraged. One should not assume that self-settling refugees are able to live with ethnic kin, receive assistance and hospitality, and thus are better off than those in camps. The Zambian case provides ample evidence that integration is not easy even with kin support, shared ethnicity, language, and historical connections. Moreover, given the fact that Zambia will continue to receive refugees it is vital that there is a well defined refugee policy and an administrative mechanism for implementing that policy at all levels. This will be particularly important in Zambia as it will undoubtedly continue to receive large influxes of refugees, from countries such as Namibia, Uganda, Angola, Mozambique, and South Africa.

  13. Self-completeness and spontaneous dimensional reduction

    Science.gov (United States)

    Mureika, Jonas; Nicolini, Piero

    2013-07-01

    A viable quantum theory of gravity is one of the biggest challenges physicists are facing. We discuss the confluence of two highly expected features which might be instrumental in the quest of a finite and renormalizable quantum gravity —spontaneous dimensional reduction and self-completeness. The former suggests the spacetime background at the Planck scale may be effectively two-dimensional, while the latter implies a condition of maximal compression of matter by the formation of an event horizon for Planckian scattering. We generalize such a result to an arbitrary number of dimensions, and show that gravity in higher than four dimensions remains self-complete, but in lower dimensions it does not. In such a way we established an "exclusive disjunction" or "exclusive or" (XOR) between the occurrence of self-completeness and dimensional reduction, with the goal of actually reducing the unknowns for the scenario of the physics at the Planck scale. Potential phenomenological implications of this result are considered by studying the case of a two-dimensional dilaton gravity model resulting from dimensional reduction of the Einstein gravity.

  14. Spontaneous Coronary Artery Dissection: Diagnosis and Management.

    Science.gov (United States)

    Yeo, Ilhwan; Feldman, Dmitriy N; Kim, Luke K

    2018-03-17

    Spontaneous coronary artery dissection (SCAD) is a non-iatrogenic and non-traumatic separation of the coronary arterial wall. While SCAD represents an important cause of myocardial infarction, optimal diagnostic and therapeutic options remain challenging. We sought to review recent studies and provide an update on diagnosis and management of SCAD. Coronary angiography is the first-line diagnostic modality for SCAD, with three angiographic features commonly observed in SCAD: type 1 (pathognomonic angiographic appearance with contrast staining of the arterial wall), type 2 (long coronary stenosis), and type 3 (focal tubular stenosis). In addition, adjunctive intracoronary imaging can aid in identifying coronary dissections. Conservative management with beta-blockers and aspirin remains the mainstay of therapy. However, patients with high-risk features and recurrent symptoms may require revascularization. Several techniques have been reported, such as long stents to seal the entire length of the dissection, stepwise stenting starting at the distal edge followed by proximal edge stenting, use of bioabsorbable stents, and cutting balloon angioplasty. Furthermore, cardiac rehabilitation appears to be safe and offers significant benefits for patients with SCAD. Coronary angiographic classification contributed to the increased recognition of SCAD in recent years. Selecting the most suitable and appropriate therapy based on accurate diagnosis is the cornerstone of management in SCAD. Further studies are needed to establish optimal treatment of SCAD depending on anatomical and/or clinical features.

  15. Spontaneous Cervical Artery Dissection: The Borgess Classification

    Directory of Open Access Journals (Sweden)

    Firas eAl-Ali

    2013-09-01

    Full Text Available ABSTRACTBackground and Purpose: The pathogenesis of spontaneous cervical artery dissections (sCAD and its best medical treatment are debated. This may be due to a lack of clear classification of sCAD. We propose the new Borgess classification of sCAD, based on the presence or absence of intimal tear as depicted on imaging studies and effect on blood flow. Materials and Methods: This is a single-center investigator-initiated registry on consecutive patients treated for sCAD. In the Borgess classification, type I dissections have intact intima and type II dissections have an intimal tear. Results: Forty-four patients and 52 dissected arteries were found. Forty-nine of 52 dissections (93% were treated with dual anti-platelet therapy. Twenty-one of 52 dissections were type I; 31 were type II. Type I dissections were more likely to present with ischemic symptoms (stroke, TIA (p=0.001. More type I dissections occurred in the vertebral artery, while more type II dissections occurred in the internal carotid artery (p

  16. Current management of spontaneous coronary artery dissection.

    Science.gov (United States)

    Bastante, Teresa; Cuesta, Javier; García-Guimaraes, Marcos; Rivero, Fernando; Maruri, Ramon; Adlan, David; Alfonso, Fernando

    2017-08-01

    Spontaneous coronary artery dissection (SCAD) remains an infrequent and elusive clinical entity of unknown etiology. However, our knowledge of SCAD has been significantly enriched in recent years. Large and prospective contemporary series have increased the interest in this disease with fewer patients misdiagnosed and a growing number of cases recognized in daily clinical practice. Classically, SCAD was thought to present mainly in young women without traditional atherosclerotic risk factors but, actually, most patients are middle-aged and are not free from coronary risk factors. A high number of associated conditions have been reported. Of these, fibromuscular dysplasia emerges as a major association with intriguing pathophysiological implications. Areas covered: This review aims to present a contemporary update on SCAD. We concentrate on the clinical scenario, related conditions, practical management and treatment strategies. Expert commentary: Recognition of SCAD is currently much more frequent and accurate as a result of increased clinical awareness and the widespread use of intravascular imaging techniques. Hopefully, in the near future an improvement in the management of SCAD patients will come not only from empirical evidence but also from dedicated clinical trials.

  17. Clinical features of multiple spontaneous intracerebral hemorrhages

    Directory of Open Access Journals (Sweden)

    Tao CHANG

    2016-01-01

    Full Text Available Objective To analyze the clinical features of multiple spontaneous intracerebral hemorrhages (MICH. Methods Conservative therapy, puncture and drainage, hematoma removal and/or decompressive craniectomy were used in the treatment of 630 intracerebral hemorrhage (ICH patients, who were divided into 2 groups: 30 cases with MICH and another 600 cases with solitary intracerebral hemorrhage (SICH. Three months after onset, modified Rankin Scale (mRS was used to evaluate the prognosis of all cases. Results Compared with patients in SICH group, the occurrence rate of hypertension > 5 years (P = 0.008, diabetes mellitus (P = 0.024, hypercholesterolemia (P = 0.050 and previous ischemic stroke (P = 0.026 were all significantly higher in MICH group. The mean arterial pressure (MAP level (P = 0.002 and the incidence of limb movement disorder (P = 0.000 were significantly higher in patients with MICH than those with SICH. Basal ganglia and thalamus were the predilection sites of hematoma (P = 0.001. Patients with MICH had worse prognosis compared to those with SICH 3 months after onset (P = 0.006. Conclusions Hypertension > 5 years, diabetes mellitus, hypercholesterolemia and ischemic stroke were identified to be the pathophysiological basis of MICH in this study. All patients with MICH had more serious clinical manifestations after onset and worse prognosis. DOI: 10.3969/j.issn.1672-6731.2016.01.008

  18. Spontaneous canine hydrocephalus: cerebrospinal fluid dynamics1

    Science.gov (United States)

    Sahar, A.; Hochwald, G. M.; Kay, W. J.; Ransohoff, J.

    1971-01-01

    Cerebrospinal fluid dynamics were studied in 14 dogs with spontaneous hydrocephalus. In nine of the dogs aqueductal obstruction was observed and the remainder had a `communicating type' hydrocephalus. The major histological findings consisted of severe ependymal destruction, spongy changes in the periventricular white matter, increased density of capillaries in this area, and varying degrees of thickening, fibrosis, and fusion of the choroid villi. The formation and absorption of CSF were studied by perfusion of the cerebral ventricles. The rate of formation of CSF was found to decrease with perfusion pressure by Vf = 0·02595−0·00022 P ml./min (P = pressure in cm H2O). The absorption of spinal fluid was found to increase linearly with pressure by Va = 0·0165 + 0·00050 P. The various factors influencing the formation and absorption of the spinal fluid are discussed. The meaning and attainment of `arrest' of the hydrocephalic process in terms of the measured rates of CSF formation and absorption in these animals are considered. Images PMID:5571319

  19. Spontaneous Pneumomediastinum with a Rare Presentation

    Directory of Open Access Journals (Sweden)

    Ehsan Bolvardi

    2014-01-01

    Full Text Available Spontaneous pneumomediastinum is an unusual and benign condition in which air is present in mediastinum. A 20-year-old male patient presented to ED with complaint of hoarseness and odynophagia from the day before, after weightlifting. The patient was nonsmoker and denied history of other diseases. On physical examination he had no dyspnea with normal vital signs. Throat examination and pulmonary auscultation were normal and no crepitation was palpable. We could not find subcutaneous emphysema in neck and chest examination. In neck and chest X-ray we found that air is present around the trachea. There was no apparent pneumothorax in CXR. In cervical and chest CT free air was present around trachea and in mediastinum. Subcutaneous emphysema was also evident. But there was no pneumothorax. The patient was admitted and went under close observation, oxygen therapy, and analgesic. The pneumomediastinum and subcutaneous emphysema gradually resolved within a week by conservative therapy and he was discharged without any complication. Many different conditions could be trigged because of pneumomediastinum but it is rarely seen in intense physical exertion such as weightlifting and bodybuilding. Two most common symptoms are retrosternal chest pain and dyspnea. But the patient here complained of hoarseness and odynophagia.

  20. [Spontaneous hepatic hematoma in twin pregnancy].

    Science.gov (United States)

    Quesnel, Carlos; Weber, Alejandro; Mendoza, Dalila; Garteiz, Denzil

    2012-02-01

    The hepatic hematoma or rupture appear in 1 of every 100,000 pregnancies. The most common causes of hepatic hematoma in pregnancy are severe preeclampsia and HELLP syndrome; some predisposing factors are seizures, vomiting, labor, preexistent hepatic disease and trauma. A 33 year old primigravid with a normal 33 week twin pregnancy presented abdominal pain and hypovolemic shock due to spontaneous subcapsular hepatic hematoma; laparoscopy was performed to evaluate the possibility of rupture, which was not found, later emergency cesarean section was carried out followed by hepatic hematoma drainage and abdominal packaging by laparoscopy. After surgery the flow through drainage was too high additionally hemodynamic instability and consumption coagulopathy. Abdominal panangiography was performed without identifying bleeding areas. Intesive care was given to the patient evolving satisfactorily, was discharged 19 days after the event. Seven months later she had laparoscopic cholecystectomy due to acute litiasic colecistitis. We found 5 cases in literatura about hepatic hematoma during pregnancy no related to hypertensive disorders of pregnancy; these were related to hepatoma, amebian hepatic abscess, falciform cell anemia, cocaine consumption and molar pregnancy. Hepatics hematomas have high morbidity and mortality so is significant early diagnosis and multidisciplinary approach.

  1. Spontaneous Blinking from a Tribological Viewpoint.

    Science.gov (United States)

    Pult, Heiko; Tosatti, Samuele G P; Spencer, Nicholas D; Asfour, Jean-Michel; Ebenhoch, Michael; Murphy, Paul J

    2015-07-01

    The mechanical forces between the lid wiper and the ocular surface, and between a contact lens and the lid wiper, are reported to be related to dry eye symptoms. Furthermore, the mechanical forces between these sliding partners are assumed to be related to the ocular signs of lid-wiper epitheliopathy (LWE) and lid-parallel conjunctival folds (LIPCOF). Recent literature provides some evidence that a contact lens with a low coefficient of friction (CoF) improves wearing comfort by reducing the mechanical forces between the contact lens surface and the lid wiper. This review discusses the mechanical forces during spontaneous blinks from a tribological perspective, at both low and high sliding velocities, in a healthy subject. It concludes that the coefficient of friction of the ocular surfaces appears to be strongly comparable to that of hydrophilic polymer brushes at low sliding velocity, and that, with increased sliding velocity, there is no wear at the sliding partners' surfaces thanks to the presence of a fluid film between the two sliding partners. In contrast, in the case of dry eye, the failure to maintain a full fluid film lubrication regime at high blinking speeds may lead to increased shear rates, resulting in deformation and wear of the sliding pairs. These shear rates are most likely related to tear film viscosity. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Enhancement of Pleasure during Spontaneous Dance

    Science.gov (United States)

    Bernardi, Nicolò F.; Bellemare-Pepin, Antoine; Peretz, Isabelle

    2017-01-01

    Dancing emphasizes the motor expression of emotional experiences. The bodily expression of emotions can modulate the subjective experience of emotions, as when adopting emotion-specific postures and faces. Thus, dancing potentially offers a ground for emotional coping through emotional enhancement and regulation. Here we investigated the emotional responses to music in individuals without any prior dance training while they either freely danced or refrained from movement. Participants were also tested while imitating their own dance movements but in the absence of music as a control condition. Emotional ratings and cardio-respiratory measures were collected following each condition. Dance movements were recorded using motion capture. We found that emotional valence was increased specifically during spontaneous dance of groovy excerpts, compared to both still listening and motor imitation. Furthermore, parasympathetic-related heart rate variability (HRV) increased during dance compared to motor imitation. Nevertheless, subjective and physiological arousal increased during movement production, regardless of whether participants were dancing or imitating. Significant correlations were found between inter-individual differences in the emotions experienced during dance and whole-body acceleration profiles. The combination of movement and music during dance results in a distinct state characterized by acutely heightened pleasure, which is of potential interest for the use of dance in therapeutic settings. PMID:29238298

  3. Timing of spontaneous sleep-paralysis episodes.

    Science.gov (United States)

    Girard, Todd A; Cheyne, J Allan

    2006-06-01

    The objective of this prospective naturalistic field study was to determine the distribution of naturally occurring sleep-paralysis (SP) episodes over the course of nocturnal sleep and their relation to bedtimes. Regular SP experiencers (N = 348) who had previously filled out a screening assessment for SP as well as a general sleep survey were recruited. Participants reported, online over the World Wide Web, using a standard reporting form, bedtimes and subsequent latencies of spontaneous episodes of SP occurring in their homes shortly after their occurrence. The distribution of SP episodes over nights was skewed to the first 2 h following bedtime. Just over one quarter of SP episodes occurred within 1 h of bedtime, although episodes were reported throughout the night with a minor mode around the time of normal waking. SP latencies following bedtimes were moderately consistent across episodes and independent of bedtimes. Additionally, profiles of SP latencies validated self-reported hypnagogic, hypnomesic, and hypnopompic SP categories, as occurring near the beginning, middle, and end of the night/sleep period respectively. Results are consistent with the hypothesis that SP timing is controlled by mechanisms initiated at or following sleep onset. These results also suggest that SP, rather than uniquely reflecting anomalous sleep-onset rapid eye movement (REM) periods, may result from failure to maintain sleep during REM periods at any point during the sleep period. On this view, SP may sometimes reflect the maintenance of REM consciousness when waking and SP hallucinations the continuation of dream experiences into waking life.

  4. Do positive spontaneous thoughts function as incentive salience?

    Science.gov (United States)

    Rice, Elise L; Fredrickson, Barbara L

    2017-08-01

    The present work explores the theoretical relationship between positive spontaneous thoughts and incentive salience-a psychological property thought to energize wanting and approach motivation by rendering cues that are associated with enjoyment more likely to stand out to the individual when subsequently encountered in the environment (Berridge, 2007). We reasoned that positive spontaneous thoughts may at least be concomitants of incentive salience, and as such, they might likewise mediate the effect of liking on wanting. In Study 1, 103 adults recruited via Amazon's Mechanical Turk reported on key aspects of 10 everyday activities. As predicted, positive spontaneous thoughts mediated the relationship between liking an activity in the past and wanting to engage in it in the future. In Study 2, 99 undergraduate students viewed amusing and humorless cartoons and completed a thought-listing task, providing experimental evidence for the causal effect of liking on positive spontaneous thoughts. In Study 3, we tested whether positive spontaneous thoughts play an active role in energizing wanting rather than merely co-occurring with (inferred) incentive salience. In that experiment involving 80 undergraduates, participants who were led to believe that their spontaneous thoughts about a target activity were especially positive planned to devote more time to that activity over the coming week than participants who received no such information about their spontaneous thoughts. Collectively, these findings suggest that positive spontaneous thoughts may play an important role in shaping approach motivation. Broader implications and future directions in the study of positive spontaneous thoughts are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Spontaneous bacterial empyema in cirrhotic patients: analysis of eleven cases.

    Science.gov (United States)

    Xiol, X; Castellote, J; Baliellas, C; Ariza, J; Gimenez Roca, A; Guardiola, J; Casais, L

    1990-03-01

    Eleven episodes of spontaneous bacterial empyema were identified in eight cirrhotic patients with ascites. Criteria for spontaneous bacterial empyema included positive pleural fluid culture or polymorphonuclear cell concentration greater than 500 cells/mm3, evidence of pleural effusion before an infectious episode and transudate characteristics during infection. In five cases, spontaneous bacterial empyema was culture-negative and was associated with spontaneous bacterial peritonitis. Ascitic fluid was culture-negative in two of these cases and culture-positive in three. Blood cultures were negative in all five of these cases. In six cases spontaneous bacterial empyema was culture-positive (Escherichia coli in four, Klebsiella pneumoniae in one and Clostridium perfringens in one). Four of these patients had the same organism in ascites; one had culture-negative spontaneous bacterial peritonitis and one had no infection of ascites. Blood cultures were positive in four of these patients; three died. Death was more frequent in patients with positive cultures than in those with negative ones (p less than 0.05). Patients with hydrothorax are prone to spontaneous bacterial empyema. This infection probably occurs through hematogenous seeding, but transfer of infected ascites from the abdominal cavity through the diaphragm cannot be excluded. Patients with spontaneous bacterial empyema may be asymptomatic or may be seen with fever, chills and dyspnea. Spontaneous bacterial empyema must be differentiated from parapneumonic empyemas. The presence of pleural effusion before the infectious episode, fluid characteristics and the organisms isolated are the clues for differential diagnosis. Treatment includes antibiotics; chest tube insertion probably is not necessary.

  6. Factors affecting the spontaneous mutational spectra in somatic mammalian cells

    Directory of Open Access Journals (Sweden)

    О.А. Ковальова

    2006-04-01

    Full Text Available  In our survey of references we are discussed the influence of factors biological origin on the spontaneous mutation specters in mammalian. Seasonal and age components influence on the frequence of cytogenetic anomalies. The immune and endocrinous systems are take part in control of the alteration of the spontaneous mutation specters. Genetical difference of sensibility in animal and human at the alteration of factors enviroment as and  genetical differences of repair systems activity are may influence on individual variation of spontaneous destabilization characters of chromosomal apparatus.

  7. Acupuncture and Spontaneous Regression of a Radiculopathic Cervical Herniated Disc

    Directory of Open Access Journals (Sweden)

    Kim Sung-Ha

    2012-06-01

    Full Text Available The spontaneous regression of herniated cervical discs is not a well-established phenomenon. However, we encountered a case of a spontaneous regression of a severe radiculopathic herniated cervical disc that was treated with acupuncture, pharmacopuncture, and herb medicine. The symptoms were improved within 12 months of treatment. Magnetic resonance imaging (MRI conducted at that time revealed marked regression of the herniated disc. This case provides an additional example of spontaneous regression of a herniated cervical disc documented by MRI following non-surgical treatment.

  8. Acupuncture and spontaneous regression of a radiculopathic cervical herniated disc.

    Science.gov (United States)

    Kim, Sung-Ha; Park, Man-Young; Lee, Sang-Mi; Jung, Ho-Hyun; Kim, Jae-Kyoun; Lee, Jong-Deok; Kim, Dong-Woung; Yeom, Seung-Ryong; Lim, Jin-Young; Park, Min-Jung; Park, Se-Woon; Kim, Sung-Chul

    2012-06-01

    The spontaneous regression of herniated cervical discs is not a well-established phenomenon. However, we encountered a case of a spontaneous regression of a severe radiculopathic herniated cervical disc that was treated with acupuncture, pharmacopuncture, and herb medicine. The symptoms were improved within 12 months of treatment. Magnetic resonance imaging (MRI) conducted at that time revealed marked regression of the herniated disc. This case provides an additional example of spontaneous regression of a herniated cervical disc documented by MRI following non-surgical treatment.

  9. Geometry of spontaneously broken local N=1 supersymmetry in superspace

    International Nuclear Information System (INIS)

    Ivanov, E.A.

    1989-01-01

    The authers reveal the model-independent geometric content of spontaneous breakdown of local supersymmetry in N=1 supergravities (conformal and minimal Einstien ones) via constructing nonlinear realizations of their underlying superspace gauge group. A general method of implementing such realizations consistently with the intrinsic superspace geometry of supergravity theories is proposed and its relevance to description of spontaneous symmetry breaking in the theories of similar nature (strings, membranes) is pointed out. Superspace adequate to the nonlinear realizations constructed and find the explicit relation between them and conventional curved N=1 superspaces are defined. The implications of this relationship for the N = 1 supergravity actions with spontaneously broken supersymmetry are discussed. 29 refs

  10. Teaching spontaneous responses to a young child with Down syndrome.

    Science.gov (United States)

    Feeley, Kathleen; Jones, Emily

    2008-10-01

    Children with Down syndrome experience significant communication impairments, particularly in expressive language. Although receiving little attention in the literature, deficiencies in expressive language are likely to affect spontaneous communicative responses in children with Down syndrome. In this study, using a multiple baseline design across responses, we demonstrated the effectiveness of discrete trial instruction in establishing spontaneous responses in a preschooler with Down syndrome. Spontaneous responses generalised to a novel setting involving a novel person and novel materials. Implications for the use of behaviourally based interventions to address the social-communicative needs of children with Down syndrome are discussed.

  11. Spontaneous and cytokine induced basophil adhesion evaluated by microtiter assay

    DEFF Research Database (Denmark)

    Quan, Sha; Poulsen, Lars K; Reimert, Claus Michael

    2002-01-01

    We have developed a microtiter assay for evaluating basophil spontaneous adhesion to extracellular matrix (ECM) proteins exemplified by fibronectin and cytokine induced basophil adhesion to bovine serum albumin (BSA). The percentage of basophils adhering to either ECM or BSA was quantified...... by the histamine content of the adhering basophils. The spontaneous adhesion to fibronectin was higher than to laminin and collagen type I. Both spontaneous adhesion to fibronectin and interleukin-3 (IL-3), interleukin-5 (IL-5), granulocyte/macrophage colony stimulating factor (GM-CSF) induced adhesion to BSA...

  12. Q-feber som årsag til spontan abort

    DEFF Research Database (Denmark)

    Nielsen, Stine Yde; Mølbak, Kåre; Hjøllund, Niels Henrik

    2011-01-01

    Q-fever is a zoonotic infection. Pregnant women constitute a specific risk group as the infection may cause spontaneous abortion, intrauterine death, growth retardation, oligohydramnios and premature birth. A 39 year-old veterinarian had a spontaneous abortion in pregnancy week seven. During...... the first weeks of her pregnancy, she handled birth by-products from cows with Q-fever. The Q-fever titres revealed that she was most likely infected in very early pregnancy. According to the literature, infection in the first trimester constitutes a specific risk of spontaneous abortion....

  13. [Spontaneous coronary artery dissection (SCAD): about 2 cases].

    Science.gov (United States)

    Elkasimi, Abdelouahab; Elouazzani, Ghizlane; Hbali, Anas; Ismaili, Nabila; Elouafi, Nouha

    2017-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome (ACS); its prevalence is estimated to be less than 3%. It is defined as a separation within the coronary arterial wall secondary to intramural bleeding with or without intimal tear, creating a false channel. It mainly affects young subjects, mainly women, without coronary atherosclerosis or risk factors for atherosclerosis. However, the occurrence of spontaneous dissection due to atheromatous disease is possible. We here report 2 cases of spontaneous coronary dissection, in order to discuss its pathogenesis, factors favoring its occurrence, its clinical presentation and its therapeutic management.

  14. Strong evidence for spontaneous chiral symmetry breaking in (quenched) QCD

    International Nuclear Information System (INIS)

    Barbour, I.M.; Gibbs, P.; Schierholz, G.; Teper, M.; Gilchrist, J.P.; Schneider, H.

    1983-09-01

    We calculate the chiral condensate for all quark masses using Kogut-Susskind fermions in lattice-regularized quenched QCD. The large volume behaviour of at small quark masses demonstrates that the explicit U(1) chiral symmetry is spontaneously broken. We perform the calculation for β = 5.1 to 5.9 and find very good continuum renormalization group behaviour. We infer that the spontaneous breaking we observe belongs to continuum QCD. This constitutes the first unambiguous demonstration of spontaneous chiral symmetry breaking in continuum quenched QCD. (orig.)

  15. Spontaneous pneumothorax and pneumomediastinum in IPF

    International Nuclear Information System (INIS)

    Franquet, T.; Gimenez, A.; Torrubia, S.; Sabate, J.M.; Rodriguez-Arias, J.M.

    2000-01-01

    Patients with idiopathic pulmonary fibrosis (IPF) are at risk for a variety of acute pulmonary complications, including pneumothorax and pneumomediastinum. Our aim was to describe the radiographic and CT findings and to determine the frequency of complicating spontaneous pneumothorax and pneumomediastinum in patients with IPF. A retrospective study was performed including 78 consecutive patients who underwent CT scanning of the chest and who had confirmed IPF. The chest radiographs and CT scans were reviewed by two chest radiologists and classified as showing features of extra-alveolar air collections. The CT scans showed extra-alveolar air in 9 (11.2 %) of 78 patients (six females and three males; age range 26-90 years, mean age 65 years). Pneumothorax was demonstrated in 5 patients and mediastinal air collections in 4 patients. All patients had dyspnea for 1-48 months (mean 14 months). Of the five cases with pneumothorax, four developed acute onset of dyspnea and pleuritic chest pain, whereas 1 patient had a relatively stable functional status. Of the 4 patients with pneumomediastinum, three presented with nonpleuritic chest pain and acute dyspnea. Chest radiographs showed extra-alveolar air in 6 patients. Three cases were predicted to be negative by chest radiographs. Follow-up CT showed that air collections had resolved completely in 5 patients. Two patients died of respiratory failure within 4 months after CT. Extra-alveolar air should be recognized as a relatively common IPF-related complication. Chest CT is a useful imaging method in determining air collections in patients with IPF that become acutely breathless and their chest radiograph fails to reveal the presence of extra-alveolar air. (orig.)

  16. Probiotics and refractory chronic spontaneous urticaria.

    Science.gov (United States)

    Nettis, E; Di Leo, E; Pastore, A; Distaso, M; Zaza, I; Vacca, M; Macchia, L; Vacca, A

    2016-09-01

    Background. In chronic spontaneous urticaria (CSU) first-line therapy with an antihistamine-based regimen may not achieve satisfactory control in patients. Thus, a continuing need exists for effective and safe treatments for refractory CSU. Aim. To evaluate the clinical efficacy and safety of an intake of a combination of 2 probiotics (Lactobacillus salivarius LS01 and Bifidobacterium breve BR03) in patients with CSU who remain symptomatic despite concomitant H1-antihistamine therapy. Methods. This report analyzes the effects of therapy with two probiotic strains on the clinical progress of 52 unselected patients with difficulty to treat CSU underwent to medical examination in two Italian specialist urticaria Clinics between September 2013 and September 2014. A mixture of Lactobacillus LS01 and Bifidobacterium BR03 were administered in each patient twice daily for 8 weeks. To evaluate patients' improvement with probiotics, urticaria activity score over 7 days (UAS7) was used at baseline and at week 8 in addition to a 5-question urticaria quality of life questionnaire. Results. Fifty-two patients with CSU were included in this study (10 male and 42 female, age range 19-72 years). Mean disease duration was 1.5 years. Fourteen patients discontinued treatment, so evaluable population consisted of 38 patients. Nine of the 38 patients experienced mild clinical improvement during probiotic treatment (23.7%); one patient reported significant clinical improvement (2.6%) and one patient had complete remission of urticaria (2.6%). Twenty-seven patients did not have improvement in symptoms (71.1%). No side effects during the course of therapy were reported. Conclusions. A combination of Lactobacillus salivarius LS01 and Bifidobacterium breve BR03 administered twice daily for 8 weeks might reduce the symptoms scores and improve quality of life scores in a part of patients with CSU who remained symptomatic despite treatment with H1 antihistamine mostly in subjects with allergic

  17. Cigarette, alcohol, and caffeine consumption: risk factors for spontaneous abortion

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2003-01-01

    OBJECTIVE: To study the association between cigarette, alcohol, and caffeine consumption and the occurrence of spontaneous abortion. METHODS: The study population consisted of 330 women with spontaneous abortion and 1168 pregnant women receiving antenatal care. A case-control design was utilized......; cases were defined as women with a spontaneous abortion in gestational week 6-16 and controls as women with a live fetus in gestational week 6-16. The variables studied comprise age, parity, occupational situation, cigarette, alcohol, and caffeine consumption. The association between cigarette, alcohol......, and caffeine consumption was studied using logistic regression analyzes while controlling for confounding variables. In addition stratified analyzes of the association between caffeine consumption and spontaneous abortion on the basis of cigarette and alcohol consumption were performed. RESULTS: Women who had...

  18. Spontaneous choledochal cyst rupture in pregnancy with concomitant chronic pancreatitis.

    Science.gov (United States)

    Pal, Sandip; Simon, Ebby George; Koshy, Anoop K; Ramakrishna, B S; Raju, Ravish S; Vyas, Fredrick L; Joseph, Philip; Sitaram, V; Eapen, Anu

    2013-03-01

    Choledochal cysts are rare cystic transformations of the biliary tree that are increasingly diagnosed in adult patients. We report here a case of spontaneous rupture of a choledochal cyst in a pregnant young lady with chronic pancreatitis.

  19. Cigarette, alcohol, and caffeine consumption: risk factors for spontaneous abortion

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2003-01-01

    given birth twice or more previously had increased odds ratio (OR), 1.78 (1.27-2.49), whereas women who were students had decreased OR, 0.55 (0.34-0.91) for having spontaneous abortions. Regarding lifestyle factors, the adjusted ORs among women who consumed 5 units or more alcohol per week or 375 mg......OBJECTIVE: To study the association between cigarette, alcohol, and caffeine consumption and the occurrence of spontaneous abortion. METHODS: The study population consisted of 330 women with spontaneous abortion and 1168 pregnant women receiving antenatal care. A case-control design was utilized......; cases were defined as women with a spontaneous abortion in gestational week 6-16 and controls as women with a live fetus in gestational week 6-16. The variables studied comprise age, parity, occupational situation, cigarette, alcohol, and caffeine consumption. The association between cigarette, alcohol...

  20. Treatment of ascites and spontaneous bacterial peritonitis - Part I

    DEFF Research Database (Denmark)

    Bendtsen, Flemming; Grønbæk, Henning; Hansen, Jesper Bach

    2012-01-01

    National guidelines for treatment of ascites, spontaneous bacterial peritonitis, hepatorenal syndrome, and hyponatremia have been approved by the Danish Society of Gastroenterology and Hepatology. Ascites develops in approximately 60% of patients with cirrhosis during a 10 year period...

  1. Renormalization of extended QED with spontaneously broken supersymmetry

    International Nuclear Information System (INIS)

    Sibold, K.

    1980-01-01

    Using the BPHZ subtraction scheme in the version of Lowenstein and Zimmermann gauge and supersymmetry Ward identities are proved to all orders of perturbation theory for the super QED where supersymmetry is spontaneously broken. (orig.)

  2. Spontaneous Tumour Lysis Syndrome in a Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Can Huzmeli

    2016-01-01

    Full Text Available The tumor lysis syndrome (TLS is a collection of metabolic abnormalities that occur in consequence of the release of intracellular contents following lysis of tumor cells. TLS occurs spontaneously or after chemotherapy. Spontaneous TLS is uncommon occurrence in multiple myeloma (MM. We define a case of a 70-year-old woman patient who was found to have MM with spontaneous TLS, following a compression fracture of the T-12 vertebrae. While serum uric acid and phosphorous levels were high, low calcium levels were identified. There were also acute kidney injury and metabolic acidosis. Upon the diagnosis of TLS, she was treated with hydration, allopurinol, sodium bicarbonate, and calcium gluconate. The improvement of her laboratory data was observed. We submitted this case in order to draw attention to the presentation of MM with spontaneous TLS.

  3. Fetal megacystis : prediction of spontaneous resolution and outcome

    NARCIS (Netherlands)

    Fontanella, F.; Duin, L.; Adama van Scheltema, P. N.; Cohen-Overbeek, T. E.; Pajkrt, E.; Bekker, M.; Willekes, C.; Bax, C. J.; Bilardo, C. M.

    2017-01-01

    Objectives: To investigate the natural history of fetal megacystis from diagnosis in utero to postnatal outcome, and to identify prognostic indicators of spontaneous resolution and postnatal outcome after resolution. Methods: This was a national retrospective cohort study. Fetal megacystis was

  4. Shared risk aversion in spontaneous and induced abortion

    DEFF Research Database (Denmark)

    Catalano, Ralph; Bruckner, Tim A.; Karasek, Deborah

    2016-01-01

    STUDY QUESTION: Does the incidence of spontaneous abortion correlate positively over conception cohorts with the incidence of non-clinically indicated induced abortion as predicted by shared risk aversion? SUMMARY ANSWER: We find that the number of spontaneous and non-clinically indicated induced...... abortions correlates in conception cohorts, suggesting that risk aversion affects both the conscious and non-conscious mechanisms that control parturition. WHAT IS KNOWN ALREADY: Much literature speculates that natural selection conserved risk aversion because the trait enhanced Darwinian fitness. Risk...... and spontaneous abortion over time. STUDY DESIGN, SIZE, DURATION: Using data from Denmark, we test the hypothesis that monthly conception cohorts yielding unexpectedly many non-clinically indicated induced abortions also yield unexpectedly many spontaneous abortions. The 180 month test period (January 1995...

  5. Spontaneous ignition due to intentional acute aluminum phosphide poisoning.

    Science.gov (United States)

    Shadnia, Shahin; Soltaninejad, Kambiz

    2011-02-01

    Acute aluminum phosphide (AlP) poisoning is one of the most common cause of acute pesticide poisoning in Iran. Spontaneous ignition is a rare finding in AlP poisoning. To present two cases of fatal AlP poisoning that involved spontaneous ignition. Two patients presented with suicidal ingestion of AlP tablets. In the Emergency Department (ED), they received gastric lavage. During insertion of a nasogastric tube, both patients experienced spontaneous ignition, and flames were witnessed by the medical personnel. Unfortunately, both patients died due to systemic effects of AlP poisoning. Patients who present with acute aluminum phosphide poisoning may experience spontaneous ignition in the ED. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Immunoglobulin G antisperm antibodies and prediction of spontaneous pregnancy

    NARCIS (Netherlands)

    Leushuis, Esther; van der Steeg, Jan Willem; Steures, Pieternel; Repping, Sjoerd; Schöls, Willem; van der Veen, Fulco; Mol, Ben Willem J.; Hompes, Peter G. A.

    2009-01-01

    Objective: To investigate the predictive capacity of immunoglobulin G ASA (direct MAR test) for spontaneous ongoing pregnancy in subfertile couples. Design: Prospective cohort study. Setting: Nine fertility centers in The Netherlands. Patient(s): Consecutive ovulatory subfertile couples.

  7. Cigarette, alcohol, and caffeine consumption: risk factors for spontaneous abortion

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2003-01-01

    , and caffeine consumption was studied using logistic regression analyzes while controlling for confounding variables. In addition stratified analyzes of the association between caffeine consumption and spontaneous abortion on the basis of cigarette and alcohol consumption were performed. RESULTS: Women who had......OBJECTIVE: To study the association between cigarette, alcohol, and caffeine consumption and the occurrence of spontaneous abortion. METHODS: The study population consisted of 330 women with spontaneous abortion and 1168 pregnant women receiving antenatal care. A case-control design was utilized......; cases were defined as women with a spontaneous abortion in gestational week 6-16 and controls as women with a live fetus in gestational week 6-16. The variables studied comprise age, parity, occupational situation, cigarette, alcohol, and caffeine consumption. The association between cigarette, alcohol...

  8. Spontaneity and Equilibrium: Why "?G Equilibrium" Are Incorrect

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The fundamental criteria for chemical reactions to be spontaneous in a given direction are generally incorrectly stated as ?G equilibrium are also misstated as being ?G = 0 or ?A = 0. Following a brief review of the…

  9. Spontaneous Breaking of Spatial and Spin Symmetry in Spinor Condensates

    DEFF Research Database (Denmark)

    Scherer, M.; Lücke, B.; Gebreyesus, G.

    2010-01-01

    Parametric amplification of quantum fluctuations constitutes a fundamental mechanism for spontaneous symmetry breaking. In our experiments, a spinor condensate acts as a parametric amplifier of spin modes, resulting in a twofold spontaneous breaking of spatial and spin symmetry in the amplified...... broken, but phase squeezing prevents spin-symmetry breaking. If, however, nondegenerate spin modes contribute to the amplification, quantum interferences lead to spin-dependent density profiles and hence spontaneously formed patterns in the longitudinal magnetization....... clouds. Our experiments permit a precise analysis of the amplification in specific spatial Bessel-like modes, allowing for the detailed understanding of the double symmetry breaking. On resonances that create vortex-antivortex superpositions, we show that the cylindrical spatial symmetry is spontaneously...

  10. Spontaneous decoherence of coupled harmonic oscillators confined in a ring

    Science.gov (United States)

    Gong, ZhiRui; Zhang, ZhenWei; Xu, DaZhi; Zhao, Nan; Sun, ChangPu

    2018-04-01

    We study the spontaneous decoherence of coupled harmonic oscillators confined in a ring container, where the nearest-neighbor harmonic potentials are taken into consideration. Without any external symmetry-breaking field or surrounding environment, the quantum superposition state prepared in the relative degrees of freedom gradually loses its quantum coherence spontaneously. This spontaneous decoherence is interpreted by the gauge couplings between the center-of-mass and the relative degrees of freedoms, which actually originate from the symmetries of the ring geometry and the corresponding nontrivial boundary conditions. In particular, such spontaneous decoherence does not occur at all at the thermodynamic limit because the nontrivial boundary conditions become the trivial Born-von Karman boundary conditions when the perimeter of the ring container tends to infinity. Our investigation shows that a thermal macroscopic object with certain symmetries has a chance for its quantum properties to degrade even without applying an external symmetry-breaking field or surrounding environment.

  11. Spontaneous infarction of hyperplastic breast tissue: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Eun Young; Nam, Sang Yu; Choi, Hye Young; Hong, Min Ji [Dept. of Radiology, Gil Medical Center, Gachon University School of Medicine and Science, Incheon (Korea, Republic of)

    2015-09-15

    Spontaneous breast infarction is a very rare complication of fibroadenoma of the breast. We present an interesting case of a 33-year-old woman with spontaneous infarction of hyperplastic breast tissue related to pregnancy and lactation. Mammography showed an oval, circumscribed, fat-containing mass with microcalcifications. Ultrasonography revealed an oval, circumscribed mass with echogenic dots. Color Doppler imaging revealed presence of minimal vascularity at the periphery of the mass.

  12. Teaching Spontaneous Responses to Young Children With Autism

    OpenAIRE

    Jones, Emily A; Feeley, Kathleen M; Takacs, Jennifer

    2007-01-01

    Using a multiple probe design across responses, we demonstrated the effectiveness of intensive intervention in establishing spontaneous verbal responses to 2 3-year-old children with autism with generalization to novel settings involving novel persons. Intervention involved discrete-trial instruction (i.e., repeated instructional opportunities presented in close proximity to high rates of reinforcement), specific prompts, and error correction. Spontaneous responses were defined as specific ve...

  13. Spontaneous expulsive suprachoroidal hemorrhage caused by decompensated liver disease

    Directory of Open Access Journals (Sweden)

    Krishnagopal Srikanth

    2013-01-01

    Full Text Available Expulsive suprachoroidal hemorrhage can be surgical or spontaneous. Spontaneous expulsive suprachoroidal hemorrhage (SESCH is a rare entity. Most of the reported cases of SESCH were caused by a combination of corneal pathology and glaucoma. We are reporting a rare presentation of SESCH with no pre-existing glaucoma or corneal pathology and caused by massive intra- and peri-ocular hemorrhage due to decompensated liver disease.

  14. Spontaneous emission of semiconductors in the Wigner approach

    Science.gov (United States)

    Filinov, V. S.; Hoyer, W.; Bonitz, M.; Kira, M.; Fortov, V. E.; Koch, S. W.

    2003-06-01

    This paper presents a first step towards combining two well-established methods used in semiconductor physicsmdashsemiconductor Bloch equations and the Wigner approach to quantum transport. This combination provides the possibility of including spontaneous emission, i.e., the spontaneous recombination of excited electron-hole pairs in semiconductors, into the Wigner approach, which so far has been used only for systems with fixed particle number. The theory is presented and first numerical results for a three-dimensional system are shown.

  15. Learning sculpts the spontaneous activity of the resting human brain

    OpenAIRE

    Lewis, Christopher M.; Baldassarre, Antonello; Committeri, Giorgia; Romani, Gian Luca; Corbetta, Maurizio

    2009-01-01

    The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brai...

  16. Highly Efficient Spontaneous Emission from Self-Assembled Quantum Dots

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Lund-Hansen, Toke; Hvam, Jørn Märcher

    2006-01-01

    We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency.......We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency....

  17. Idiopathic Spontaneous Adrenal Hemorrhage in the Third Trimester of Pregnancy

    Directory of Open Access Journals (Sweden)

    Narin Nasiroglu Imga

    2013-01-01

    Full Text Available Spontaneous adrenal hemorrhage (SAH is seen in the absence of trauma or adrenal tumor in adrenal glands. The incidence of SAH has been reported from 0.14% to 1.1% and it usually involves the right gland. During pregnancy, idiopathic unilateral SAH has been reported rarely. We present a case which comes to emergency department with an acute abdominal pain and the test results showed spontaneous left SAH.

  18. [Atypical etiology of rhinorrhea: spontaneous bilateral temporal encephalocele].

    Science.gov (United States)

    Lorente Muñoz, Asís; Lisbona Alquézar, María Pilar; González Martínez, Luis; Sevil Navarro, Jorge; Llorente Arenas, Eva María

    2012-01-01

    Spontaneous herniation of brain parenchyma through a dural and osseous defect in the temporal bone is a rare entity and a bilateral form is even more infrequent. It usually presents as an intermittent but persistent otorrhea. Manifestation as nose cerebrospinal fluid (CSF) leak is very uncommon. Our objective is presenting this unusual case report of a spontaneous bilateral encephalocele with a bilateral tegmen tympani defect. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  19. Spontaneous acute subdural hematoma in a patient with multiple myeloma

    Directory of Open Access Journals (Sweden)

    Abrar Ahad Wani

    2012-01-01

    Full Text Available Acute spontaneous subdural hematoma in a patient of multiple myeloma receiving chemotherapy is an unknown event, needing an urgent neurosurgical management. We report this patient who presented with progressive neurological deterioration and a low platelet count. She was successfully managed by craniotomy and evacuation of subdural hematoma with intraoperative transfusion of platelets. The acute spontaneous subdural hematoma in her was probably related to the bleeding diathesis due to thrombocytopenia associated with chemotherapy.

  20. Spontaneous Rupture of the Stomach; Report of Case,

    Science.gov (United States)

    1980-07-30

    massively distended and she experienced dyspnea. She developed tachycardia (110) and became hypotensive (90 systolic). Portable x-rays of the chest and...pointed out by Matikainen 17 in 1979. Spontaneous gastric rupture in the newborn appears to be more common than in the adult. 18 DISCUSSION The cause of...138:(451-452), 1979. 18. Bayatpour, M., Bernard, L., McCune, F., and bariel, W.: Spontaneous gastric rupture in the newborn , Am. J. Surg., 137:(267-269), 1979.

  1. Spontaneous Tricuspid Valve Chordal Rupture in Idiopathic Pulmonary Hypertension.

    Science.gov (United States)

    Rodrigues, Ana Clara Tude; Afonso, José E; Cordovil, Adriana; Monaco, Claudia; Piveta, Rafael; Cordovil, Rodrigo; Fischer, Claudio H; Vieira, Marcelo; Lira-Filho, Edgar; Morhy, Samira S

    2016-03-01

    Rupture of tricuspid valve is unusual, occurring mainly in the setting of blunt trauma or endomyocardial biopsy. Spontaneous tricuspid valve chordal rupture is particularly rare. We report herein a case of a patient with severe pulmonary hypertension, on the lung transplantation waiting list, who presented with spontaneous chordal rupture, exacerbation of tricuspid insufficiency and worsening of clinical status. Diagnosis and treatment, along with possible mechanisms for this complication, are discussed. © 2015, Wiley Periodicals, Inc.

  2. Spontaneous remission of a diffuse brainstem lesion in a neonate

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Leena; Kahn, Thomas [University of Leipzig, Department of Diagnostic and Interventional Radiology, Leipzig (Germany); Merkenschlager, Andreas [University of Leipzig, Department of Pediatric Neurology, Leipzig (Germany); Hirsch, Wolfgang [University of Leipzig, Pediatric Radiology, Department of Diagnostic and Interventional Radiology, Leipzig (Germany)

    2007-04-15

    We describe here the spontaneous remission of a diffuse brainstem lesion found in an infant at the age of 7 weeks. Clinical and MRI characteristics strongly suggested a diffuse pontine glioma. Repeated MRI studies showed a continuous decrease in the size of the lesion, which was no longer visible by the age of 27 months. Spontaneous remission of diffuse pontine glioma is extremely rare; to our knowledge there are reports of only three similar cases. (orig.)

  3. Spontaneous Regression of Intervertebral Disc Herniation – Case Reports

    OpenAIRE

    Rapan, Saša; Gulan, Gordan; Lovrić, Ivan; Jovanović, Savo

    2011-01-01

    Lumbar disc hernia (LDH) is a common cause of low back pain and radicular leg pain. It is well known that the majority of LDH patients recover spontaneously. Since the advent of MRI, a spontaneous regression of fragment size of disc hernia occurs, as well as mitigation of subjective difficulties and neurological disorders. Therefore, surgical treatment is not always method of choice in this disease. Two cases of conservatively treated large disc extrusion which result in significant ...

  4. Trisomy 13 ascertained in a survey of spontaneous abortions.

    OpenAIRE

    Jacobs, P A; Hassold, T J; Henry, A; Pettay, D; Takaesu, N

    1987-01-01

    In a series of 2922 karyotyped spontaneous abortions, 62 were found to be trisomic for chromosome 13, 46 having a simple trisomy and 16 a translocation trisomy. The epidemiology of this series of trisomy 13 conceptuses is presented and compared to that of trisomy 13 ascertained from other populations. In most compared parameters the trisomy 13 spontaneous abortions are very similar. However, there is no evidence in our material for the fall in proportion of trisomy 13 conceptuses at very adva...

  5. Ferrihydrite flocs, native copper nanocrystals and spontaneous remediation in the Fosso dei Noni stream, Tuscany, Italy

    International Nuclear Information System (INIS)

    Genovese, Alessandro; Mellini, Marcello

    2007-01-01

    The Fosso dei Noni stream drains the abandoned mixed-sulfide mining area of Fenice Capanne in Italy. Water pollution mostly derives from two tributaries, one of which adds Cu and the other Zn. Downstream, water pollution is progressively remediated through the spontaneous precipitation of abundant, deeply-colored flocs. Within 1 km, flocs change from yellow-red to whitish and green, as the pH increases from 4.59 to 7.70 and the Eh decreases from +311 to +165 mV. Flocs are initially amorphous; with a near-neutral pH, their X-ray diffraction properties suggest the presence of two-line ferrihydrite. Transmission electron microscopy reveals major nanotextural modifications in flocs along the entire stream. Upstream, flocs consist of globular particles with a radius of 25-50 nm. Downstream, they change to globular particles with elongated features. Lastly, further downstream, flocs consist of elongated features interconnected by continuous films. Nanochemical data are consistent with Al and Fe hydroxides (largely contaminated by S, Si, Ca, Cu and Zn); the Cu content increases progressively downstream to a maximum of 18 at. %. The increasing Cu content is paralleled by the appearance of isolated Cu nanocrystals adsorbed on floc surfaces. Spontaneous processes in the Fosso dei Noni stream (water neutralization, formation of ferrihydrite-like flocs and crystallization of native Cu) allow the temporary storage of Cu, providing hints on how to optimize remediation processes and Cu recovery

  6. l-arginine supplementation reduces cardiac noradrenergic neurotransmission in spontaneously hypertensive rats

    OpenAIRE

    Lee, Chee-Wan; Li, Dan; Channon, Keith M.; Paterson, David J.

    2009-01-01

    Spontaneously hypertensive rats (SHR) are known to have cardiac noradrenergic hyperactivity due to an impaired nitric oxide (NO)?cGMP pathway. We hypothesized that dietary l-arginine supplementation may correct this autonomic phenotype. Male SHR and Wistar Kyoto rats (WKY) aged 16?18?weeks were given l-arginine (10?g/L in drinking water) for 1?week. Separate control groups received no supplementation. The SHR control had a significantly lower plasma l-arginine than WKY control, but this was i...

  7. Comparative study of the antihypertensive activity of Marrubium vulgare and of the dihydropyridine calcium antagonist amlodipine in spontaneously hypertensive rat.

    Science.gov (United States)

    El Bardai, Sanae; Lyoussi, Badiaa; Wibo, Maurice; Morel, Nicole

    2004-08-01

    Water extract of Marrubium vulgare is widely used as antihypertensive treatment in folk medicine. We have compared the effect of 10-week-long treatment with amlodipine or Marrubium water extract on systolic blood pressure (SBP), cardiovascular remodeling and vascular relaxation in spontaneously hypertensive rats (SHR). Both treatments produced similar decrease in SBP. Amlodipine treatment reduced left ventricle, aortic and mesenteric artery weight. Marrubium treatment had a significant antihypertrophic effect in aorta only. Relaxation to acetylcholine (ACh) of mesenteric artery was improved by Marrubium but not by amlodipine treatment. These results demonstrate that, in addition to its antihypertensive effect, Marrubium water extract improved the impaired endothelial function in SHR.

  8. Spontaneous indices are inconsistent with arterial baroreflex gain.

    Science.gov (United States)

    Lipman, Ruth D; Salisbury, Julie K; Taylor, J Andrew

    2003-10-01

    Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, alpha-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except alpha-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.

  9. Group-theoretic condition for spontaneous CP violation

    Science.gov (United States)

    Haber, Howard E.; Surujon, Ze'ev

    2012-10-01

    We formulate the necessary conditions for a scalar potential to exhibit spontaneous CP violation. Associated with each complex scalar field is a U(1) symmetry that may be explicitly broken by terms in the scalar potential (called spurions). In order for CP-odd phases in the vacuum to be physical, these phases must be related to spontaneously broken U(1) generators that are also explicitly broken by a sufficient number of inequivalent spurions. In the case where the vacuum is characterized by a single complex phase, our result implies that the phase must be associated with a U(1) generator that is broken explicitly by at least two inequivalent spurions. A suitable generalization of this result to the case of multiple complex phases has also been obtained. These conditions may be used both to distinguish models capable of spontaneous CP violation and as a model building technique for obtaining spontaneously CP-violating deformations of CP-conserving models. As an example, we analyze the generic two Higgs doublet model, where we also carry out a complete spurion analysis. We also comment on other models with spontaneous CP violation, including the chiral Lagrangian, a minimal version of the Nelson-Barr model, and little Higgs models with spontaneous CP violation.

  10. Observation time and spontaneous resolution of primary phimosis in children

    Directory of Open Access Journals (Sweden)

    Pedro Luiz Toledo de Arruda Lourenção

    Full Text Available ABSTRACT Objective: to investigate spontaneous resolution rate of a series of patients with physiologic phimosis in relation to observation time and presence of symptoms. Methods: retrospective and longitudinal follow-up study of patients with physiologic phimosis, that did not apply topic treatment. These patients were invited for a new visit for reevaluation, or recent data were obtained by chart analysis. Spontaneous resolution rate was determined and statistically compared to age, presence of symptoms at first medical visit and time until reevaluation. Results: seventy one patients were included. Medium time of observation from first visit to reevaluation was 37.4 months. There was spontaneous resolution of phimosis in 32 (45% patients. Children with spontaneous resolution were younger at initial diagnosis and were observed during a longer period of time. Most asymptomatic patients at first visit presented spontaneous resolution. However, it was not possible to stablish a significant relationship between presence of symptoms and evolution of physiologic phimosis. Conclusions: time of observation was the main determinant of spontaneous resolution of patients with physiologic phimosis, reinforcing the current more conservative approach regarding circumcision of those patients.

  11. Sustained mild hypergravity reduces spontaneous cardiac baroreflex sensitivity.

    Science.gov (United States)

    Yanagida, Ryo; Ogawa, Yojiro; Ueda, Kaname; Aoki, Ken; Iwasaki, Ken-ichi

    2014-10-01

    Head-to-foot gravitational force >1G (+Gz hypergravity) augments venous pooling in the lower body and reduces central blood volume during exposure, compared with 1Gz. Central hypovolemia has been reported to reduce spontaneous cardiac baroreflex sensitivity. However, no investigations have examined spontaneous cardiac baroreflex sensitivity during exposure to sustained mild +Gz hypergravity. We therefore hypothesized that mild +Gz hypergravity would reduce spontaneous cardiac baroreflex sensitivity, compared with 1Gz. To test this hypothesis, we examined spontaneous cardiac baroreflex sensitivity in 16 healthy men during exposure to mild +Gz hypergravity using a short-arm centrifuge. Beat-to-beat arterial blood pressure (tonometry) and R-R interval (electrocardiography) were obtained during 1Gz and 1.5Gz exposures. Spontaneous cardiac baroreflex sensitivity was assessed by sequence slope and transfer function gain. Stroke volume was calculated from the arterial pressure waveform using a three-element model. All indices of spontaneous cardiac baroreflex sensitivity decreased significantly (up slope: 18.6±2.3→12.7±1.6ms/mmHg, Pbaroreflex sensitivity, increasing the risk of cardiovascular disturbance during the exposure. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Spontaneous symmetry breaking: formation of Janus micelles

    NARCIS (Netherlands)

    Voets, I.K.; Fokkink, R.G.; Hellweg, T.; King, S.M.; Waard, de P.; Keizer, de A.; Cohen Stuart, M.A.

    2009-01-01

    We describe the preparation and solution properties of Janus micelles, i.e., non-centrosymmetric nanoparticles with compartmentalized shells, via co-assembly of two fully water-soluble block copolymers. They consist of a mixed core of poly(N-methyl-2-vinyl pyridinium iodide) (P2MVP) and poly(acrylic

  13. Pathogenesis of hypercalciuria in spontaneously hypertensive rats.

    Science.gov (United States)

    Hsu, C H; Chen, P S; Smith, D E; Yang, C S

    1986-01-01

    The etiology of hypercalciuria remains unknown in spontaneously hypertensive rats (SHR). In order to differentiate absorptive versus renal hypercalciuria, serial measurements of urinary calcium (UCaV) excretion were made weekly under fasting (3-hour urine collection) and after oral administration of CaCl2 (50 mg/100 g; 4-hour urine collection) from age 8 to 14 weeks in SHR (n = 14) and normotensive Wistar Kyoto rats (WKY; n = 14). Fasting UCaV was significantly greater in WKY than in SHR throughout the periods of observation. In contrast, after oral Ca loading UCaV was greater in SHR after 13 weeks of age (13 weeks: SHR UCaV = 954 micrograms/mg creatinine, WKY UCaV = 541 p less than 0.01; 14 weeks: SHR UCaV = 988 micrograms/mg creatinine, WKY UCaV = 534, p less than 0.01). Fasting urinary cyclic adenosine monophosphate (AMP) excretion was not different between WKY and SHR. However, cyclic AMP excretion of SHR, but not WKY, was decreased after calcium loading when compared to the fasting values. The cyclic AMP was also significantly lower in SHR than in WKY rats after calcium loading. Calcium handling by the kidney was not different between SHR and WKY with or without parathyroidectomy. Calcium disposition kinetic studies were performed on these animals at age 15 and 16 weeks. No significant difference of intravenous 45Ca was observed between WKY (n = 6) and SHR (n = 6) in total plasma clearance, nonrenal clearance, biologic half-life, and elimination rate constant from the central compartment. However, the WKY had a significantly greater renal clearance of 45Ca than the SHR (0.48 +/- 0.04 vs. 0.24 +/- 0.02 ml/n, p less than 0.001). Since tissue disposition of intravenous 45Ca was not different between WKY and SHR, the increased renal excretion of calcium after oral administration in SHR, therefore, reflects increased intestinal absorption of calcium. Correction of established hypertension did not abolish the hypercalciuria. We believe that increased

  14. Shared risk aversion in spontaneous and induced abortion.

    Science.gov (United States)

    Catalano, Ralph; Bruckner, Tim A; Karasek, Deborah; Adler, Nancy E; Mortensen, Laust H

    2016-05-01

    Does the incidence of spontaneous abortion correlate positively over conception cohorts with the incidence of non-clinically indicated induced abortion as predicted by shared risk aversion? We find that the number of spontaneous and non-clinically indicated induced abortions correlates in conception cohorts, suggesting that risk aversion affects both the conscious and non-conscious mechanisms that control parturition. Much literature speculates that natural selection conserved risk aversion because the trait enhanced Darwinian fitness. Risk aversion, moreover, supposedly influences all decisions including those that individuals can and cannot report making. We argue that these circumstances, if real, would manifest in conscious and non-conscious decisions to invest in prospective offspring, and therefore affect incidence of induced and spontaneous abortion over time. Using data from Denmark, we test the hypothesis that monthly conception cohorts yielding unexpectedly many non-clinically indicated induced abortions also yield unexpectedly many spontaneous abortions. The 180 month test period (January 1995 through December 2009), yielded 1 351 800 gestations including 156 780 spontaneous as well as 233 280 induced abortions 9100 of which were clinically indicated. We use Box-Jenkins transfer functions to adjust the incidence of spontaneous and non-clinically indicated induced abortions for autocorrelation (including seasonality), cohort size, and fetal as well as gestational anomalies over the 180-month test period. We use cross-correlation to test our hypothesized association. We find a positive association between spontaneous and non-clinically indicated induced abortions. This suggests, consistent with our theory, that mothers of conception cohorts that yielded more spontaneous abortions than expected opted more frequently than expected for non-clinically indicated induced abortion. Limitations of our work include that even the world's best registration system

  15. The clinical and laboratory characteristics of acute spontaneous urticaria and its progression to chronic spontaneous urticaria.

    Science.gov (United States)

    Magen, Eli; Zueva, Ekaterina; Mishal, Joseph; Schlesinger, Menachem

    2016-09-01

    The natural history of the progression from acute spontaneous urticaria (ASU) to chronic spontaneous urticaria (CSU), CSU remains poorly understood. To identify clinical and laboratory patient attributes that may be predictive of ASU progression to CSU. We prospectively studied consecutive adult patients (age ≥ 18 years) with a diagnosis of urticaria of urticaria activity score assessment were performed in all the patients at baseline and then at weeks 7, 12, 24, and 48. Of 114 patients with acute urticaria and without identifiable causes, 73 patients (64%) were included in the ASU group, 41 patients in the CSU group (36%), and 44 healthy subjects in the control group. At baseline, 26 patients in the CSU group (63.4%) had a positive ASST result, whereas only 17 patients with a positive ASST result (23.3%) were revealed in the ASU group (p < 0.001). Patients with baseline ASST positive results were characterized by more profound basopenia (mean [standard deviation], 0.05 ± 0.08 cell/mm(3)) and more anti-thyroid peroxidase antibodies (18 [41.8%]) than those with the negative baseline ASST result (mean [standard deviation], 0.13 ± 0.09 cell/mm(3), p < 0.001 more profound basopenia; and 13 (18.1%), p = 0.009 more thyroid peroxidase antibodies). We observed the disappearance of ASST positive result in some patients with CSU with baseline positive ASST results, whereas, in some subjects with CSU, baseline negative ASST results came to be positive results throughout the study period. A baseline positive ASST result of patients with ASU was a significant determinant (odds ratio 5.91 [95% confidence interval, 2.57-13.62]; p < 0.001) for a CSU diagnosis at week 7. The patients with ASU who progressed toward CSU were characterized by a positive ASST result, thyroid autoimmunity, and profound basopenia at baseline.

  16. Uncovering intrinsic modular organization of spontaneous brain activity in humans.

    Directory of Open Access Journals (Sweden)

    Yong He

    Full Text Available The characterization of topological architecture of complex brain networks is one of the most challenging issues in neuroscience. Slow (<0.1 Hz, spontaneous fluctuations of the blood oxygen level dependent (BOLD signal in functional magnetic resonance imaging are thought to be potentially important for the reflection of spontaneous neuronal activity. Many studies have shown that these fluctuations are highly coherent within anatomically or functionally linked areas of the brain. However, the underlying topological mechanisms responsible for these coherent intrinsic or spontaneous fluctuations are still poorly understood. Here, we apply modern network analysis techniques to investigate how spontaneous neuronal activities in the human brain derived from the resting-state BOLD signals are topologically organized at both the temporal and spatial scales. We first show that the spontaneous brain functional networks have an intrinsically cohesive modular structure in which the connections between regions are much denser within modules than between them. These identified modules are found to be closely associated with several well known functionally interconnected subsystems such as the somatosensory/motor, auditory, attention, visual, subcortical, and the "default" system. Specifically, we demonstrate that the module-specific topological features can not be captured by means of computing the corresponding global network parameters, suggesting a unique organization within each module. Finally, we identify several pivotal network connectors and paths (predominantly associated with the association and limbic/paralimbic cortex regions that are vital for the global coordination of information flow over the whole network, and we find that their lesions (deletions critically affect the stability and robustness of the brain functional system. Together, our results demonstrate the highly organized modular architecture and associated topological properties in

  17. Genotype x year interaction for cooking time and its correlation with mass and imbibition percentage on food type soybean/ Interação genótipo x ano para tempo de cozimento e sua correlação com a massa e percentagem de embebição em soja tipo alimento

    Directory of Open Access Journals (Sweden)

    Anderson Paranzini Faria

    2005-06-01

    Full Text Available Brazil is second in soybean world production and it is responsable for 26.8% of the global production. Soybean grains have 40% of protein and 20% of oil. Soybean grains are rich in isoflavones, which prevent degenerative cronic diseases. With the increasing use of soybean for human consumption, there is necessity to study how the environment effects the grain technological characteristics. Many technological processes in soybean industrialization involve imbibition and cooking. The objective of this work was to select soybean genotypes for human consumption, by determining cooking time and its correlation with mass and grain imbibition percentages, taking into consideration genotype, agricultural year and their interaction. The following traits were determined: weight of one hundred seeds, imbibition percentage and cooking time. Cooking time was measured by a modified Mattson Machine. Significant differences (O Brasil é o segundo produtor mundial de soja (Glycine Max (L. Merrill, sendo responsável por 26,8% da safra global. A soja possuí 40% de proteína e 20% de óleo. A soja é rica em isoflavonas, as quais atuam na prevenção de doenças crônicas degenerativas. Com o crescente uso da soja na alimentação humana, há necessidade de se estudar como o ambiente influencia nas características tecnológicas do grão. Muitos dos processos tecnológicos de industrialização da soja possuem como ponto inicial a hidratação e posterior cozimento da soja. O objetivo deste trabalho foi selecionar genótipos de soja para o consumo humano, através da determinação do tempo de cozimento e sua correlação com a massa e percentagem de embebição dos grãos, levando-se em consideração genótipo, ano agrícola e sua interação. Foram determinados os seguintes caracteres: massa de cem grãos, percentagem de embebição e tempo de cozimento. O tempo de cozimento foi determinado por meio da Máquina de Mattson adaptada. Foram encontradas diferen

  18. Spatial diversity of spontaneous activity in the cortex

    Directory of Open Access Journals (Sweden)

    Andrew Yong-Yi Tan

    2015-09-01

    Full Text Available The neocortex is a layered sheet across which a basic organization is thought to widely apply. The variety of spontaneous activity patterns is similar throughout the cortex, consistent with the notion of a basic cortical organization. However, the basic organization is only an outline which needs adjustments and additions to account for the structural and functional diversity across cortical layers and areas. Such diversity suggests that spontaneous activity is spatially diverse in any particular behavioral state. Accordingly, this review summarizes the laminar and areal diversity in cortical activity during fixation and slow oscillations, and the effects of attention, anesthesia and plasticity on the cortical distribution of spontaneous activity. Among questions that remain open, characterizing the spatial diversity in spontaneous membrane potential may help elucidate how differences in circuitry among cortical regions supports their varied functions. More work is also needed to understand whether cortical spontaneous activity not only reflects cortical circuitry, but also contributes to determining the outcome of plasticity, so that it is itself a factor shaping the functional diversity of the cortex.

  19. Spontaneous emission near non-trivial conducting surfaces

    International Nuclear Information System (INIS)

    Melo e Souza, Reinaldo de; Kort-Kamp, W.J.M.; Taddei, M.M.; Farina, C.

    2013-01-01

    Full text: One of the remarkable phenomena associated with the zero-point fluctuations of the electromagnetic field is the spontaneous emission, which accounts for the emission of photons by an excited atom placed in vacuum. As discovered by Purcell in the 1940's, the spontaneous emission rate depends not only on the atomic properties but also on the nearby bodies. This should be expected once the electromagnetic field modes are affected by the boundary conditions imposed by these bodies. We begin our presentation reviewing a method which establishes a striking connection between the spontaneous emission of an excited atom and the classical radiation emitted by an oscillating real dipole. In fact, it can be shown, the influence of the neighbouring bodies is the same in both cases. We use this approach to evaluate the influence of an infinite conducting plane with a circular aperture on the spontaneous emission rate of the atom. This geometry will be particularly interesting if the atom is placed on the axis of symmetry of the hole and if it is predominantly polarizable in this axis, once this configuration is one of the those rare configurations that give rise to repulsive dispersive interactions. It would be very interesting to establish some connection between how the spontaneous emission rate of an excited atom is influenced by the presence of material bodies and the attractive or repulsive character of the dispersive force between that atom (in its ground state) and those material bodies. (author)

  20. Spontaneous Intracerebral Hemorrhage: Computed Tomographic Characteristics and Outcome

    Directory of Open Access Journals (Sweden)

    Aimara de la Caridad Vergara Santos

    2015-12-01

    Full Text Available Background: strokes are the third leading cause of death among adults and 10-15 % of them are due to spontaneous intracerebral hemorrhage. Objective: to characterize spontaneous intracerebral hemorrhage through computed tomography scan and its outcome. Methods: a case series study was conducted comprising patients diagnosed with spontaneous intracerebral hemorrhage admitted to the Arnaldo Milián Castro Provincial University Hospital in Villa Clara from January 2009 to January 2010. Tomographic variables of interest were derived from evaluation of spontaneous intracerebral hematomas. Results: fifty-nine cases of spontaneous intracerebral hemorrhage were studied, 23 were located in lobar regions, 4 had severe midline shift, and 2 showed volume greater than 80 ml. Eight out of eleven with extension into the ventricular system had an unfavorable outcome. Among those with thalamic hemorrhage, patients with diameter larger than 4cm and extension into the ventricular system died. Patients with putaminal hemorrhage larger than 4 cm and posterior fossa hematoma with hydrocephalus had a poor outcome, as well as most individuals (55 with other mass effects. Most lobar hematomas (14 out of 23 had a satisfactory outcome, unlike cerebellar and brainstem hematomas. Conclusions: tomographic variables that had a negative impact on the outcome were: volume greater than 80 ml, severe midline shift, diameter larger than 4 cm, extension into the ventricular system, hydrocephalus, other signs of mass effect and brainstem location.

  1. Amaranth Protein Hydrolysates Efficiently Reduce Systolic Blood Pressure in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Giovanni Ramírez-Torres

    2017-11-01

    Full Text Available Alcalase is the enzyme of choice to release antihypertensive peptides from amaranth proteins, but the hydrolysis conditions have not been optimized yet. Furthermore, in vivo assays are needed to confirm such a hypotensive effect. Our aim was to optimize the hydrolysis of amaranth protein with alcalase and to test in vivo the hypotensive effect of the hydrolysates. A response surface analysis was carried out to optimize the hydrolysis reaction. The response variable was the Angiotensin Converting Enzyme (ACE-I inhibition. The hydrolysis degree was determined (free alpha-amino groups measurement. The optimized hydrolysate bioavailability was assessed in the sera of mice and the hypotensive effect was assessed in spontaneously hypertensive rats. Control groups were administered captopril or water. The optimized hydrolysis conditions were: pH = 7.01, temperature = 52 °C, enzyme concentration 0.04 mU/mg, and time = 6.16 h. The optimized hydrolysate showed a 93.5% of ACE-I inhibition and a hydrolysis degree of 74.77%. After supplementation, the hydrolysate was bioavailable in mice from 5 to 60 min, and the hypotensive effect started at 4 h in spontaneously hypertensive rats (p < 0.05 vs. water group. This effect was similar to the captopril hypotensive effect for the next 3 h (p > 0.05. The use of amaranth-optimized hydrolysates as hypotensive supplements or ingredient for functional foods seems feasible.

  2. Spontaneous uterine perforation due to pyometra presenting as acute abdomen.

    Science.gov (United States)

    Geranpayeh, Loabat; Fadaei-Araghi, Mohsen; Shakiba, Behnam

    2006-01-01

    Spontaneous perforation of the uterus is rare, its incidence being about 0.01%-0.05%. We report a rare case of diffuse peritonitis caused by spontaneously perforated pyometra. A 63-year-old woman with severe abdominal pain was admitted to our hospital. Laparotomy was performed because of the suspicion of gastrointestinal perforation with generalized peritonitis. At laparotomy, about 900 mL of pus was found in the peritoneal cavity. There were no abnormal findings in the alimentary tract, liver, or gallbladder. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Pathological investigation of the surgical specimen revealed endometritis and myometritis of the uterus; but there was no evidence of malignancy, and the cervical canal was patent. Although spontaneously perforated pyometra is rare, a perforated pyometra should therefore also be considered when elderly women present with acute abdominal pain.

  3. Spontaneous methicillin-resistant Staphylococcus aureus epidural abscess in pregnancy.

    Science.gov (United States)

    Connealy, Brendan D; Lovgren, Todd R; Tomich, Paul G; Smith, Carl V; Berg, Teresa G

    2010-08-01

    Epidural abscess is a rare complication of regional anesthesia, and spontaneous formation is even more uncommon. Diabetes mellitus, concomitant infection, intravenous drug use, and immune suppression are risk factors for spontaneous epidural abscess. A 29-year-old white woman presented at 28 weeks of estimated gestational age reporting an intermittent headache. She had Horner syndrome and was hospitalized. A cervicothoracic epidural abscess was diagnosed. Surgical decompression and parenteral antibiotics resulted in complete resolution of neurologic symptoms. Cultures were positive for methicillin-resistant Staphylococcus aureous. Spontaneous epidural abscess is a rare condition and diagnosis is often delayed. The finding of Horner syndrome led to imaging of the cervical spine and diagnosis of epidural abscess. Early intervention resulted in resolution of neurologic symptoms and a successful pregnancy outcome.

  4. Coherent spontaneous radiation from highly bunched electron beams

    International Nuclear Information System (INIS)

    Berryman, K.W.; Crosson, E.R.; Ricci, K.N.

    1995-01-01

    Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10 4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques

  5. Operator-product expansion with spontaneously broken symmetry

    International Nuclear Information System (INIS)

    Brown, L.S.; Lee, T.

    1989-01-01

    The operator-product expansion is a most important tool in quantum field theory, and it is often employed in theories that have a spontaneously broken symmetry such as QCD where chiral symmetry is broken. Claims have been made that the operator-product expansion does not apply to theories with a spontaneously broken symmetry. Although these claims have been previously rebutted, none of these works provide a precise and careful definition of the needed renormalized composite operators and of the operator-product expansion. This we do here for the simple case of scalar field theory. We show explicitly for the first two orders of perturbation theory that operator-product expansion does hold for the spontaneously broken theory for the case of the two-point Green's function. This we do both for the case of a single scalar field and also for the O(N) linear σ-model. copyright 1989 Academic Press, Inc

  6. Planning for spontaneous evacuation during a radiological emergency

    International Nuclear Information System (INIS)

    Johnson, J.H. Jr.

    1984-01-01

    The Federal Emergency Management Agency's (FEMA's) radiological emergency preparedness program ignores the potential problem of spontaneous evacuation during a nuclear reactor accident. To show the importance of incorporating the emergency spatial behaviors of the population at risk in radiological emergency preparedness and response plans, this article presents empirical evidence that demonstrates the potential magnitude and geographic extent of spontaneous evacuation in the event of an accident at the Long Island Lighting Company's Shoreham Nuclear Power Station. The results indicate that, on the average, 39% of the population of Long Island is likely to evacuate spontaneously and thus to cast an evacuation shadow extending at least 25 miles beyond the plant. On the basis of these findings, necessary revisions to FEMA's radiological emergency preparedness program are outlined

  7. General theory of spontaneous emission near exceptional points.

    Science.gov (United States)

    Pick, Adi; Zhen, Bo; Miller, Owen D; Hsu, Chia W; Hernandez, Felipe; Rodriguez, Alejandro W; Soljačić, Marin; Johnson, Steven G

    2017-05-29

    We present a general theory of spontaneous emission at exceptional points (EPs)-exotic degeneracies in non-Hermitian systems. Our theory extends beyond spontaneous emission to any light-matter interaction described by the local density of states (e.g., absorption, thermal emission, and nonlinear frequency conversion). Whereas traditional spontaneous-emission theories imply infinite enhancement factors at EPs, we derive finite bounds on the enhancement, proving maximum enhancement of 4 in passive systems with second-order EPs and significantly larger enhancements (exceeding 400×) in gain-aided and higher-order EP systems. In contrast to non-degenerate resonances, which are typically associated with Lorentzian emission curves in systems with low losses, EPs are associated with non-Lorentzian lineshapes, leading to enhancements that scale nonlinearly with the resonance quality factor. Our theory can be applied to dispersive media, with proper normalization of the resonant modes.

  8. Alcohol consumption at the time of conception and spontaneous abortion

    DEFF Research Database (Denmark)

    Henriksen, T.B.; Hjollund, N.H.; Jensen, Tina Kold

    2004-01-01

    The authors studied the association between female and male alcohol intakes at the time of conception and the risk of spontaneous abortion, including early pregnancy loss detected by urinary human chorionic gonadotropin. After a nationwide mailing to about 50,000 members of four trade unions....... Women collected morning urine for 10 days from the first day of vaginal bleeding in each cycle. The authors detected 186 pregnancies: 131 resulted in childbirth, and 55 resulted in spontaneous abortion (34 detected by urinary human chorionic gonadotropin). Depending on the intake in the cycle...... of conception and the adjustment factors, female alcohol intake was associated with 2-3 times the adjusted risk of spontaneous abortion compared with no intake, and male alcohol intake was associated with 2-5 times the adjusted risk. Only the adjusted relative risks for 10 or more drinks/week compared...

  9. Spontaneous Symmetry Breaking in 5D Conformally Invariant Gravity

    Directory of Open Access Journals (Sweden)

    Taeyoon Moon

    2016-01-01

    Full Text Available We explore the possibility of the spontaneous symmetry breaking in 5D conformally invariant gravity, whose action consists of a scalar field nonminimally coupled to the curvature with its potential. Performing dimensional reduction via ADM decomposition, we find that the model allows an exact solution giving rise to the 4D Minkowski vacuum. Exploiting the conformal invariance with Gaussian warp factor, we show that it also admits a solution which implements the spontaneous breaking of conformal symmetry. We investigate its stability by performing the tensor perturbation and find the resulting system is described by the conformal quantum mechanics. Possible applications to the spontaneous symmetry breaking of time-translational symmetry along the dynamical fifth direction and the brane-world scenario are discussed.

  10. Spontaneous Uterine Perforation due to Pyometra Presenting as Acute Abdomen

    Directory of Open Access Journals (Sweden)

    Loabat Geranpayeh

    2006-01-01

    Full Text Available Spontaneous perforation of the uterus is rare, its incidence being about 0.01%–0.05%. We report a rare case of diffuse peritonitis caused by spontaneously perforated pyometra. A 63-year-old woman with severe abdominal pain was admitted to our hospital. Laparotomy was performed because of the suspicion of gastrointestinal perforation with generalized peritonitis. At laparotomy, about 900 mL of pus was found in the peritoneal cavity. There were no abnormal findings in the alimentary tract, liver, or gallbladder. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Pathological investigation of the surgical specimen revealed endometritis and myometritis of the uterus; but there was no evidence of malignancy, and the cervical canal was patent. Although spontaneously perforated pyometra is rare, a perforated pyometra should therefore also be considered when elderly women present with acute abdominal pain.

  11. Spontaneous Plasticity of Multineuronal Activity Patterns in Activated Hippocampal Networks

    Directory of Open Access Journals (Sweden)

    Atsushi Usami

    2008-01-01

    Full Text Available Using functional multineuron imaging with single-cell resolution, we examined how hippocampal networks by themselves change the spatiotemporal patterns of spontaneous activity during the course of emitting spontaneous activity. When extracellular ionic concentrations were changed to those that mimicked in vivo conditions, spontaneous activity was increased in active cell number and activity frequency. When ionic compositions were restored to the control conditions, the activity level returned to baseline, but the weighted spatial dispersion of active cells, as assessed by entropy-based metrics, did not. Thus, the networks can modify themselves by altering the internal structure of their correlated activity, even though they as a whole maintained the same level of activity in space and time.

  12. Hypovolemic shock following induced abortion and spontaneous heterotopic pregnancy.

    Science.gov (United States)

    Pakniyat, Abdolghader; Yazdanbakhsh, Arash; Moshar-Mowahed, Ghasem; Talebi, Fatimah

    2015-12-01

    Spontaneous heterotopic pregnancy is a rare clinical condition in which intrauterine and extrauterine pregnancies occur at the same time. It is rare, estimated to occur in 1 in 30,000 pregnancies. The case was a 38-year-old woman with spontaneously conceived heterotopic pregnancy. She was admitted to our center with hypovolemic shock. Focused assessment sonography for trauma examination in emergency department showed large amount of free fluid in peritoneal cavity. She was managed surgical laparotomy. Considering spontaneous pregnancies, physician should be aware of the possibility of heterotopic pregnancy in all reproductive age women, especially those with history of recent abortion. It can occur without any predisposing risk factors. Patients should be informed about possible side effects of nonprescription medicines, and also the health care centers must be safe peaceful environment for them without severe legal consequences.

  13. Joseph Conrad and the spontaneous combustion of coal - Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Walters, A.D. [Kilborn Engineering Pacific Ltd., Vancouver, BC (Canada)

    1996-12-31

    Joseph Conrad`s novel `Youth` described an on-board fire and explosion from transported coal between Sumatra and Bangka Island. This incident is based on Conrad`s experience as a mariner transporting coal, and displays a detailed knowledge of the technical issues and preventative actions involved in the spontaneous combustion of coal cargoes at sea. The coal concerned was West Hartley coal, and in this article the author examines the combustion characteristics of this coal, and the historical information available on the explosion on board the `Palestine`. The reasons for spontaneous combustion are examined, with particular attention paid to oxidation, moisture content and pyrite oxidation. West Hartley coal was a high volatile bituminous coal, with high self-heating tendencies, and so likely to undergo spontaneous combustion in the right conditions. Self-heating in ships is now well researched as a result of the international maritime coal trade. 21 refs., 3 figs., 7 tabs.

  14. Qualifying phrases as a measure of spontaneity in speech.

    Science.gov (United States)

    Weintraub, W; Plaut, S M

    1985-11-01

    Although investigators have attempted to define the paralinguistic characteristics of spontaneous speech, there have been no systematic attempts to study its verbal reflections. An experiment comparing extemporaneous and impromptu speech samples of 10 freshman medical students showed that, of 10 verbal categories, only qualifying phrases significantly differentiated the two levels of spontaneity. A second study compared post-World War II presidential communications of different degrees of spontaneity. Speech samples were taken from inaugural addresses of seven presidents, and from both introductory remarks and responses to questions at their press conferences. The proportion of qualifying phrases significantly decreased as the amount of preparation increased, confirming the results of the student experiment. The use of qualifying phrases appears to represent, in part, an attempt by the speaker to avoid silence while retrieving and encoding memories from long-term storage.

  15. [Results of spontaneous NBT-test in influenza patients].

    Science.gov (United States)

    Nagoev, B S; Orazaev, N G

    2000-01-01

    Assessment of leukocyte activity with spontaneous NBT-test in influenza patients regarding the disease stage, severity, complication and concomitant diseases. 107 influenza patients aged 16-84 years were studied. 70 patients had no complications, 11 patients had early influenzal pneumonia, 26 patients had late viral-bacterial infection. Chronic concomitant diseases were diagnosed in 23 cases. Cytochemical examination of leukocyte activity was made in all the patients using spontaneous NBT-test. In mild influenza NBT-test results were within upper limits of normal value. In alleviation of the symptoms NBT-test parameters were low. In early influenzal and viral-bacterial pneumonia leukocyte activity was high and lowered to normal in late convalescence. Parameters of spontaneous NBT-test in influenzal patients were elevated depending on influenza stage, severity and complications. This fact is of differential-diagnostic importance.

  16. Metastatic thymoma presenting as spontaneous epidural lumbar haematoma.

    Science.gov (United States)

    Shivapathasundram, Ganeshwaran; Sammons, Vanessa; Bazina, Renata

    2016-05-01

    We report the case of a 44-year-old man who was found to have metastatic thymoma to his lumbar spine presenting as a spontaneous epidural haematoma. The man presented with back pain and cauda equina like symptoms in the absence of trauma, antiplatelet or anticoagulant agents. Following a laminectomy and excision of the epidural collection he made a full neurological recovery. Histopathology of the haematoma demonstrated metastatic thymoma. To the best of our knowledge, this is the first such case of metastatic thymoma to the lumbar spine presenting as a spontaneous epidural collection. We believe, in all patients with spontaneous spinal epidural haematoma and a background of malignancy, histopathological analysis should be sought.

  17. Spontaneous Hypoglycemia After Islet Autotransplantation for Chronic Pancreatitis.

    Science.gov (United States)

    Lin, Yu Kuei; Faiman, Charles; Johnston, Philip C; Walsh, R Matthew; Stevens, Tyler; Bottino, Rita; Hatipoglu, Betul A

    2016-10-01

    Spontaneous hypoglycemia has been reported in patients after total pancreatectomy (TP) and islet autotransplantation (IAT) with maintained insulin independence. Details surrounding these events have not been well described. The objective of the study was to determine the frequency and characteristics of spontaneous hypoglycemia in patients undergoing TP-IAT and/or to ascertain predictive or protective factors of its development. This was an observational cohort study in 40 patients who underwent TP-IAT from August 2008 to May 2014, with a median follow-up of 34 months. The study was conducted at a single institution (Cleveland Clinic). Patients included recipients of TP-IAT. The intervention included small, frequent meals in those patients who developed spontaneous hypoglycemia. Incidence of spontaneous hypoglycemia development, characteristics of the patients developing hypoglycemia, and their response to small, frequent meals were measured. Six of 12 patients, who maintained insulin independence, developed spontaneous hypoglycemia. The episodes could be fasting, postprandial, and/or exercise associated, with the frequency ranging from two to three times daily to once every 1-2 weeks. All patients experienced at least one episode that required external assistance, glucagon administration, and/or emergent medical attention. Patients who developed hypoglycemia had a lower median age and tended to have a lower median islet equivalent/kg body weight but a higher median total islet equivalent, body mass index, and homeostatic model assessment for insulin resistance score. All patients who received small, frequent meal intervention had improvement in severity and/or frequency of the hypoglycemic episodes. Spontaneous hypoglycemia is prevalent after TP-IAT. Although the underlying pathophysiology responsible for these hypoglycemia events remains to be elucidated, small, frequent meal intervention is helpful in ameliorating this condition.

  18. Predictors of rapid spontaneous resolution of acute subdural hematoma.

    Science.gov (United States)

    Fujimoto, Kenji; Otsuka, Tadahiro; Yoshizato, Kimio; Kuratsu, Jun-ichi

    2014-03-01

    Acute subdural hematoma (ASDH) usually requires emergency surgical decompression, but rare cases exhibit rapid spontaneous resolution. The aim of this retrospective study was to identify factors predictive of spontaneous ASDH resolution. A total of 366 consecutive patients with ASDH treated between January 2006 and September 2012 were identified in our hospital database. Patients with ASDH clot thickness >10mm in the frontoparietotemporal region and showing a midline shift >10mm on the initial computed tomography (CT) scan were divided into two groups according to subsequent spontaneous resolution. Univariate and multivariate logistic regression analyses were used to identify factors predictive of rapid spontaneous ASDH resolution. Fifty-six ASDH patients met study criteria and 18 demonstrated rapid spontaneous resolution (32%). Majority of these patients were not operated because of poor prognosis/condition and in accordance to family wishes. Univariate analysis revealed significant differences in use of antiplatelet agents before head injury and in the incidence of a low-density band between the hematoma and inner wall of the skull bone on the initial CT. Use of antiplatelet agents before head injury (OR 19.6, 95% CI 1.5-260.1, p=0.02) and the low-density band on CT images (OR 40.3, 95% CI 3.1-520.2, p=0.005) were identified as independent predictive factors by multivariate analysis. Our analysis suggested that use of antiplatelet agents before head injury and a low-density band between the hematoma and inner skull bone on CT images (indicative of cerebrospinal fluid infusion into the subdural space) increase the probability of rapid spontaneous resolution. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Spontaneous usage of different shortcuts based on the commutativity principle.

    Directory of Open Access Journals (Sweden)

    Robert Gaschler

    Full Text Available Based on research on expertise a person can be said to possess integrated conceptual knowledge when she/he is able to spontaneously identify task relevant information in order to solve a problem efficiently. Despite the lack of instruction or explicit cueing, the person should be able to recognize which shortcut strategy can be applied--even when the task context differs from the one in which procedural knowledge about the shortcut was originally acquired. For mental arithmetic, first signs of such adaptive flexibility should develop already in primary school. The current study introduces a paper-and-pencil-based as well as an eyetracking-based approach to unobtrusively measure how students spot and apply (known shortcut options in mental arithmetic. We investigated the development and the relation of the spontaneous use of two strategies derived from the mathematical concept of commutativity. Children from grade 2 to grade 7 and university students solved three-addends addition problems, which are rarely used in class. Some problems allowed the use of either of two commutativity-based shortcut strategies. Results suggest that from grade three onwards both of the shortcuts were used spontaneously and application of one shortcut correlated positively with application of the other. Rate of spontaneous usage was substantial but smaller than in an instructed variant. Eyetracking data suggested similar fixation patterns for spontaneous an instructed shortcut application. The data are consistent with the development of an integrated concept of the mathematical principle so that it can be spontaneously applied in different contexts and strategies.

  20. Spontaneous plant colonization of brownfield soil and sludges and effects on substrate properties and pollutants mobility

    Science.gov (United States)

    Rocco, Claudia; Agrelli, Diana; Gonzalez, Maria Isabel; Mingo, Antonio; Motti, Riccardo; Stinca, Adriano; Coppola, Ida; Adamo, Paola

    2017-04-01

    This work was done on brownfield soil and sludges from a dismantled steel plant, moderately polluted by heavy metals (mainly Pb and Zn), 1) to analyzed the effects of substrate properties and environmental conditions on spontaneous vegetation; 2) to assess changes in the chemical properties of soils and sludges, with particular reference to the mobility and bioavailability of pollutants, induced by spontaneous plants revegetation. From 2006 to 2011, spontaneous plant colonization was monitored in the presence or absence of acidic peat both inside the degraded brownfield site and after transferal into a nearby Oak Park environment. During the five experimental years the vegetation growth was monitored using phytosociological method and data analyzed statistically. Both substrates, before and after plant growth, were analyzed for main chemical properties. Metals mobility and bioavailability was assessed using single (H2O; DTPA) and sequential extractions (EU-BCR). At the end of the experiment, plant ability to uptake metal was evaluated on selected species. Overall, 57 plant species grew healthily on the substrates. The combination of soil and sludges with peat resulted in an effective revegetation with a sensible increasing of plants biomass. Most of the species were found in the park (91%), showing plant colonization was mainly affected by the immediate environment rather than by substrate properties. Furthermore, after the five years, the substrate properties (pH, O.C.) were slightly affected by plant growth and, although metal pollutants in both substrates are characterized by low water solubility and DTPA availability, after plants growth an increase (even if not significant) of rhizospheric Cu, Fe, Mn and Zn solubility in H2O was detected. Metals speciation indicated a low risk of Pb and Zn mobility being either largely trapped in the mineralogical structure of oxides and silicates and occluded in easily reducible manganese or iron oxides. Restricted metal

  1. An uncommon cause of ascites: spontaneous rupture of biliary cystadenoma.

    Science.gov (United States)

    Abhishek, Sasidharan; Jino, Thomas; Sarin, George Zacharia; Sandesh, Kolassery; Prathapan, Valiya Kambarath; Ramachandran, Thazhath Mavali

    2014-01-01

    Biliary cystadenomas are cystic hepatic tumours of biliary origin. Cystadenomas are often slow-growing benign tumours, but always harbour the risk of malignant transformation. Cystadenomas are often asymptomatic, but may present with abdominal pain and distension. Though suspected with cross-sectional abdominal imaging, definitive diagnosis almost always requires histology. Spontaneous rupture of cystadenoma had been reported three times in the medical literature to date, all presenting with peritonitis. Here we report a case of spontaneous intraperitoneal rupture of biliary cystadenoma presenting as ascites without peritonitis.

  2. Controlling the spontaneous emission of a superconducting transmon qubit.

    Science.gov (United States)

    Houck, A A; Schreier, J A; Johnson, B R; Chow, J M; Koch, Jens; Gambetta, J M; Schuster, D I; Frunzio, L; Devoret, M H; Girvin, S M; Schoelkopf, R J

    2008-08-22

    We present a detailed characterization of coherence in seven transmon qubits in a circuit QED architecture. We find that spontaneous emission rates are strongly influenced by far off-resonant modes of the cavity and can be understood within a semiclassical circuit model. A careful analysis of the spontaneous qubit decay into a microwave transmission-line cavity can accurately predict the qubit lifetimes over 2 orders of magnitude in time and more than an octave in frequency. Coherence times T1 and T_{2};{*} of more than a microsecond are reproducibly demonstrated.

  3. Mesoscale Architecture Shapes Initiation and Richness of Spontaneous Network Activity.

    Science.gov (United States)

    Okujeni, Samora; Kandler, Steffen; Egert, Ulrich

    2017-04-05

    Spontaneous activity in the absence of external input, including propagating waves of activity, is a robust feature of neuronal networks in vivo and in vitro The neurophysiological and anatomical requirements for initiation and persistence of such activity, however, are poorly understood, as is their role in the function of neuronal networks. Computational network studies indicate that clustered connectivity may foster the generation, maintenance, and richness of spontaneous activity. Since this mesoscale architecture cannot be systematically modified in intact tissue, testing these predictions is impracticable in vivo Here, we investigate how the mesoscale structure shapes spontaneous activity in generic networks of rat cortical neurons in vitro In these networks, neurons spontaneously arrange into local clusters with high neurite density and form fasciculating long-range axons. We modified this structure by modulation of protein kinase C, an enzyme regulating neurite growth and cell migration. Inhibition of protein kinase C reduced neuronal aggregation and fasciculation of axons, i.e., promoted uniform architecture. Conversely, activation of protein kinase C promoted aggregation of neurons into clusters, local connectivity, and bundling of long-range axons. Supporting predictions from theory, clustered networks were more spontaneously active and generated diverse activity patterns. Neurons within clusters received stronger synaptic inputs and displayed increased membrane potential fluctuations. Intensified clustering promoted the initiation of synchronous bursting events but entailed incomplete network recruitment. Moderately clustered networks appear optimal for initiation and propagation of diverse patterns of activity. Our findings support a crucial role of the mesoscale architectures in the regulation of spontaneous activity dynamics. SIGNIFICANCE STATEMENT Computational studies predict richer and persisting spatiotemporal patterns of spontaneous activity in

  4. Unilateral Post-LASIK Ectasia and Contralateral Spontaneous Ectasia.

    Science.gov (United States)

    Qin, Vincent; Saad, Alain; Gatinel, Damien

    2016-02-01

    To report a case of iatrogenic unilateral post-LASIK corneal ectasia with contralateral spontaneous ectatic evolution. Case report with preoperative and postoperative measurements including uncorrected visual acuity, corrected distance visual acuity, refraction, slit-scanning topographic and pachymetric maps, and differential maps. Six months after unilateral LASIK, the operated eye progressively developed signs of post-LASIK ectasia with increased inferior corneal steepening and corneal thinning and decrease in corrected distance visual acuity. Five years later, the unoperated eye also developed signs of spontaneous ectatic evolution with increased inferior steepening and corneal thinning. LASIK accelerates occurrence of ectasia in ectasia-susceptible and biomechanically fragile eyes. Copyright 2016, SLACK Incorporated.

  5. Spontaneous drainage in syringomyelia: magnetic resonance imaging findings

    International Nuclear Information System (INIS)

    Bogdanov, E.I.; Mendelevich, E.G.; Ibatullin, M.M.

    2000-01-01

    We present five cases of syringomyelia associated with Chiari I or other causes of partial obstructions at the cervicomedullary junction, with spontaneous disruption of the wall of a cervical syrinx and formation of a communication between the cavity and the subarachnoid space, shown on axial MRI. MRI can be used to investigate the hydrodynamics, showing the liquid inside the disrupted syrinx wall and the pathway of drainage. The finding of spontaneous drainage may be important for understanding the pathogenesis of syringomyelia and may be helpful for choosing a surgical approach. (orig.)

  6. Spontaneous Pregnancy Loss in Denmark Following Economic Downturns

    DEFF Research Database (Denmark)

    Bruckner, Tim A.; Mortensen, Laust H.; Catalano, Ralph A.

    2016-01-01

    ,449) and the unemployment rate in Denmark beginning in January 1995 and ending in December 2009. Our statistical methods controlled for temporal patterns in spontaneous abortion (e.g., seasonality, trend) and changes in the population of pregnancies at risk of loss. Unexpected increases in the unemployment rate preceded...... in elective abortions and in the cohort composition of high-risk pregnancies did not account for results. It appears that in Denmark, ambient stressors as common as increasing unemployment may precede a population-level increase in spontaneous abortion....

  7. Using Motion Tracking to Detect Spontaneous Movements in Infants

    DEFF Research Database (Denmark)

    Olsen, Mikkel Damgaard; Herskind, Anna; Nielsen, Jens Bo

    2015-01-01

    We study the characteristics of infants’ spontaneous movements, based on data obtained from a markerless motion tracking system. From the pose data, the set of features are generated from the raw joint-angles of the infants and different classifiers are trained and evaluated using annotated data....... Furthermore, we look at the importance of different features and outline the most significant features for detecting spontaneous movements of infants. Using these findings for further analysis of infants’ movements, this might be used to identify infants in risk of cerebral palsy....

  8. Spontaneous adrenal hemorrhage during pregnancy: a case with horseshoe kidney

    Directory of Open Access Journals (Sweden)

    Mohadeseh Amini

    2017-11-01

    Full Text Available Spontaneous adrenal hemorrhage is an acute hemorrhage during pregnancy, which can be tragic for the mother and the baby. We report a unique spontaneous hemorrhage during pregnancy in a case with horseshoe kidney with separated adrenal, presented for the first time in the world. Computed tomography scan showed a horseshoe kidney fused with left normal kidney. Interestingly the adrenal gland was remained in right flank and separated from the horseshoe kidney, which prepares a probable physical stress for the hemorrhage. Diagnosis and surgery were done successfully and the case was fully recovered after several days.

  9. Spontaneous symmetry breaking, self-trapping, and Josephson oscillations

    CERN Document Server

    2013-01-01

    This volume collects a a number of contributions on spontaneous symmetry breaking. Current studies in this general field are going ahead at a full speed. The book present review chapters which give an overview on the major break throughs of recent years. It covers a number of different physical settings which are introduced when a nonlinearity is added to the underlying symmetric problems and its strength exceeds a certain critical value. The corresponding loss of symmetry, called spontaneous symmetry breaking, alias self-trapping into asymmetric states is extensively discussed in this book.

  10. HLA-G polymorphisms in couples with recurrent spontaneous abortions

    DEFF Research Database (Denmark)

    Hviid, T V; Hylenius, S; Hoegh, A M

    2002-01-01

    The etiology of a fraction of recurrent spontaneous abortions (RSA) may involve immunological mechanisms. Aberrant profiles of Th1 and Th2 cytokines have been observed which are not present in uncomplicated pregnancies. Studies of classical HLA class I and II antigens in relation to RSA have...... (with three or more spontaneous abortions) and 47 fertile control couples were HLA-G genotyped by direct DNA sequencing and analyzed for specific polymorphisms. No statistically significant differences were observed in the distribution of HLA-G alleles between controls and RSA couples, however, 15...

  11. Spontaneous pregnancy during ulipristal acetate treatment of giant uterine leiomyoma.

    Science.gov (United States)

    Hrgovic, Z; Habek, D; Cerkez Habek, J; Hrgovic, I; Jerkovic Gulin, S; Gulin, D

    2018-02-01

    Ulipristal acetate, a progesterone receptor modulator, pharmacologically inhibits endometrial proliferation and thereby prevents pregnancy. It is primarily used as emergency contraception, but also for the treatment of fibroids in women of reproductive age. There have been no published cases of pregnancy, while on therapy with ulipristal acetate. In this article, we present a case report of spontaneous pregnancy during ulipristal acetate therapy. To our knowledge, this is the first patient with spontaneous conception, while on ulipristal acetate treatment. There were no drug-related complications, and the pregnancy resulted in the delivery of a healthy baby. © 2017 John Wiley & Sons Ltd.

  12. Nonclassical photon streams using rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    Ledingham, Patrick M.; Naylor, William R.; Longdell, Jevon J.; Beavan, Sarah E.; Sellars, Matthew J.

    2010-01-01

    We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission; however, this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an 'echo' of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwith quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.

  13. Multiple spontaneous bone infarcts secondary to alcohol abuse

    International Nuclear Information System (INIS)

    Wadhwa, S.S.; Mansberg, R.

    1999-01-01

    Alcohol induced spontaneous osteonecrosis is part of the differential diagnosis in patients with history of alcohol abuse and diffuse bone pain. Usually patients have a longer than 10 year history of alcohol abuse prior to the development of osteonecrosis. The femoral head is the commonest site involved, however, involvement of the long bones is also seen. Facial involvement is rarely seen. Fat embolism secondary to coexisting hyperlipidemia has been postulated as a possible cause of osteonecrosis in alcoholics. A case of multifocal spontaneous bone infarction with facial bone involvement in a 34 year old female alcoholic is described. Copyright (1999) The Australian and New Zealand Society of Nuclear Medicine Inc

  14. Spontaneous emergence of free-space optical and atomic patterns

    International Nuclear Information System (INIS)

    Schmittberger, Bonnie L; Gauthier, Daniel J

    2016-01-01

    The spontaneous formation of patterns in dynamical systems is a rich phenomenon that transcends scientific boundaries. Here, we report our observation of coupled optical–atomic pattern formation, which results in the creation of self-organized, multimode structures in free-space laser-driven cold atoms. We show that this process gives rise to spontaneous three-dimensional Sisyphus cooling even at very low light intensities and the emergence of self-organized structures on both sub- and super-wavelength scales. (paper)

  15. Spontaneous compactification and Ricci-flat manifolds with torsion

    International Nuclear Information System (INIS)

    McInnes, B.

    1985-06-01

    The Freund-Rubin mechanism is based on the equation Rsub(ik)=lambdagsub(ik) (where lambda>0), which, via Myers' Theorem, implies ''spontaneous'' compactification. The difficulties connected with the cosmological constant in this approach can be resolved if torsion is introduced and lambda set equal to zero, but then compactification ''by hand'' is necessary, since the equation Rsub(ik)=0 can be satisfied both on compact and on non-compact manifolds. In this paper we discuss the global geometry of Ricci-flat manifolds with torsion, and suggest ways of restoring the ''spontaneity'' of the compactification. (author)

  16. Water's quantum structures and life.

    Science.gov (United States)

    Germano, Roberto

    2015-01-01

    This article discusses several clues pointing to the spontaneous quantum origin of the recently discovered dissipative structures induced in liquid water by low-energy physical perturbations. These structures show an astonishing permanence, so much that large ponderal quantities of supramolecular aggregates of water - at ambient pressure and temperature - subsist even in the solid phase, strongly suggesting the possibility that these structures are the matrix itself of life.

  17. Biological response of spontaneously hypertensive rats to the streptozotocin administration

    Directory of Open Access Journals (Sweden)

    Virginia Alice Vieira da Costa

    2008-02-01

    Full Text Available The sensitivity of adult spontaneously hypertensive rats (SHR to the diabetogenic effect of streptozotocin (STZ was studied. The animals were subdivided into three groups: control (citrate buffer, streptozotocin 40 mg/kg or 50 mg/kg, and general biologic parameters were analyzed, in addition to systolic blood pressure, blood glucose and insulin levels determinations. Both doses were able to induce hyperglycemia above 300 mg/dl; however, 50 mg/kg provoked a more pronounced physiological alterations in body weight, diuresis, water and food intake. There was no change on systolic blood pressure with either dose. Results suggested that SHRs did not need doses of streptozotocin above 40mg/kg in order to produce diabetes probably because this strain was much more sensible than normotensive rats. In addition, streptozotocin might be a drug choice to induce diabetes without provoking alterations in the blood pressure which allowed the use of this experimental model in the studies of induced hypertension-diabetes.Foi estudada a sensibilidade de ratos espontaneamente hipertensos (SHR adultos ao efeito diabetogênico da estreptozotocina (STZ. Os animais foram subdivididos em grupos: controle (tampão citrato, 40 mg/kg ou 50 mg/kg de estreptozotocina, sendo analisados parâmetros biológicos gerais, pressão arterial sistólica, níveis sanguíneos de glicose e insulina. Ambas doses foram capazes de induzir hiperglicemia acima de 300 mg/dl, entretanto a dose de 50 mg/kg provocou efeitos fisiológicos mais pronunciados no peso corpóreo, diurese, ingestão hídrica e de ração. Não houve alteração da pressão arterial sistólica em qualquer dose. Nossos achados sugerem que SHRs não necessitam de doses de estreptozotocina acima de 40 mg/kg com para produzir diabetes, provavelmente porque essa cepa é muito mais sensível do que ratos normotensos. A estreptozotocina pode ser a droga de escolha para induzir diabetes sem provocar alterações na press

  18. Il?us biliaire avec ?vacuation spontan?e d?un gros calcul : a propos d?un cas

    OpenAIRE

    Hassani, Karim Ibnmajdoub; Rode, Julie; Poincenot, Jane; Gruss, Jean-Manuel

    2010-01-01

    L?il?us biliaire est une complication rare de la lithiase biliaire; Il est caract?ris? par la triade radiologique, syndrome occlusif, a?robilie et localisation ectopique d?un calcul dans le tube digestif. La cause est g?n?ralement une fistule bilio-digestive. En dehors de l??vacuation spontan?e du calcul qui est rare et int?resse surtout les calculs de moins de 2 cm, le traitement reste dans la majorit? des cas chirurgical. Nous rapportons le cas d?une patiente de 80ans, admise pour occlusion...

  19. Application of Foam-gel Technique to Control CO Exposure Generated During Spontaneous Combustion of Coal in Coal Mines.

    Science.gov (United States)

    Ren, Xing W; Wang, Feng Z; Guo, Qing; Zuo, Zhao B; Fang, Qi S

    2015-01-01

    In China, 47.3% of state-owned coal mines are located in coal seams that are prone to spontaneous combustion. The spontaneous combustion of coal is the main cause of the generation of a large amount of carbon monoxide, which can cause serious health issues to miners. A new technique using foam-gel formation was developed to effectively control the spontaneous combustion of coal. The gel can capture more than 90% of the water in the grout and at the same time the foam can cover dangerous areas in the goaf by stacking and cooling of foam in all directions. In this study, a mechanism of foam-gel formation was introduced and the optimal proportions of additives were defined based on experiments of different foaming properties, gelling time and water loss rate as the main index parameters. The results of a field application in a coal mine promise that this new technique would effectively prevent coal oxidation in the goaf and reduce the generation of carbon monoxide.

  20. Impact of Pressure and Brine Salinity on Capillary Pressure-Water Saturation Relations in Geological CO2 Sequestration

    Directory of Open Access Journals (Sweden)

    Jongwon Jung

    2016-01-01

    Full Text Available Capillary pressure-water saturation relations are required to explore the CO2/brine flows in deep saline aquifers including storage capacity, relative permeability of CO2/brine, and change to stiffness and volume. The study on capillary pressure-water saturation curves has been conducted through experimentation and theoretical models. The results show that as the pressure increases up to 12 MPa, (1 capillary pressure-water saturation curves shift to lower values at given water saturation, (2 after the drainage process, residual water saturation decreases, and (3 after the imbibition process, capillary CO2 trapping increases. Capillary pressure-water saturation curves above 12 MPa appear to be similar because of relatively constant contact angle and interfacial tension. Also, as brine salinity increases from 1 M to 3 M NaCl, (1 capillary pressure-water saturation curves shift to lower capillary pressure, (2 residual water saturation decreases, and (3 capillary CO2 trapping increases. The results show that pressure and brine salinity have an influence on the capillary pressure-water saturation curves. Also, the scaled capillary CO2 entry pressure considering contact angle and interfacial tension is inconsistent with atmospheric conditions due to the lack of wettability information. Better exploration of wettability alteration is required to predict capillary pressure-water saturation curves at various conditions that are relevant to geological CO2 sequestration.